|Publication number||US8740834 B2|
|Application number||US 13/050,855|
|Publication date||3 Jun 2014|
|Filing date||17 Mar 2011|
|Priority date||18 Jul 2007|
|Also published as||EP2173425A2, EP2173425B1, US8157760, US8784355, US9011364, US9789242, US20090024072, US20100280431, US20110166496, US20110166497, US20140371653, US20160271316, WO2009012473A2, WO2009012473A3|
|Publication number||050855, 13050855, US 8740834 B2, US 8740834B2, US-B2-8740834, US8740834 B2, US8740834B2|
|Inventors||Enrique Criado, Tony M. Chou, Michi E. Garrison, Gregory M. Hyde, Alan Schaer, Richard Renati|
|Original Assignee||Silk Road Medical, Inc.|
|Export Citation||BiBTeX, EndNote, RefMan|
|Patent Citations (353), Non-Patent Citations (49), Classifications (32), Legal Events (2)|
|External Links: USPTO, USPTO Assignment, Espacenet|
This application is a continuation of co-pending U.S. patent application Ser. No. 12/176,250, entitled “Methods and Systems for Establishing Retrograde Carotid Arterial Blood Flow”, filed on Jul. 18, 2008, which claims the benefit under 35 U.S.C. §119(e) of the following U.S. Provisional Patent Applications: (1) U.S. Provisional Patent Application Ser. No. 60/950,384 filed on Jul. 18, 2007 and (2) U.S. Provisional Patent Application Ser. No. 61/026,308 filed on Feb. 5, 2008. Priority of the aforementioned filing dates is hereby claimed, and the disclosures of the patent applications are hereby incorporated by reference in their entirety.
This application is a continuation of co-pending U.S. patent application Ser. No. 12/176,250, entitled “Methods and Systems for Establishing Retrograde Carotid Arterial Blood Flow”, filed on Jul. 18, 2008, which claims the benefit under 35 U.S.C. §119(e) of the following U.S. Provisional Patent Applications: (1) U.S. Provisional Patent Application Ser. No. 60/950,384 filed on Jul. 18, 2007 and (2) U.S. Provisional Patent Application Ser. No. 61/026,308 filed on Feb. 5, 2008. Priority of the aforementioned filing dates is hereby claimed, and the disclosures of the patent applications are hereby incorporated by reference in their entirety.
The present disclosure relates generally to medical methods and devices. More particularly, the present disclosure relates to methods and systems for accessing the carotid arterial vasculature and establishing retrograde blood flow during performance of carotid artery stenting and other procedures.
Carotid artery disease usually consists of deposits of plaque P which narrow the junction between the common carotid artery CCA and the internal carotid artery ICA, an artery which provides blood flow to the brain (
Two principal therapies are employed for treating carotid artery disease. The first is carotid endarterectomy CEA, an open surgical procedure which relies on occluding the common, internal and external carotid arteries, opening the carotid artery at the site of the disease (usually the carotid bifurcation where the common carotid artery CCA divides into the internal carotid artery ICA and external carotid artery ECA), dissecting away and removing the plaque P, and then closing the carotid artery. The second procedure relies on stenting of the carotid arteries, referred to as carotid artery stenting CAS, typically at or across the branch from the common carotid artery CAA into the internal carotid artery ICA, or entirely in the internal carotid artery. Usually, a self-expanding stent is introduced through percutaneous puncture into the femoral artery in the groin and up the aortic arch into the target common carotid artery CCA.
In both these approaches, the patient is at risk of emboli being released into the cerebral vasculature via the internal carotid artery ICA. The clinical consequence of emboli release into the external carotid artery ECA, an artery which provides blood to facial structures, is less significant. During CEA, the risk of emboli release into the internal carotid artery ICA is minimized by debriding and vigorously flushing the arteries before closing the vessels and restoring blood flow. During the procedure while the artery is opened, all the carotid arteries are occluded so particles are unable to enter the vasculature.
In carotid stenting CAS procedures, adjunct embolic protection devices are usually used to at least partially alleviate the risk of emboli. An example of these devices are distal filters, which are deployed in the internal carotid artery distal to the region of stenting. The filter is intended to capture the embolic particles to prevent passage into the cerebral vasculature. Such filtering devices, however, carry certain limitations. They must be advanced to the target vessel and cross the stenosis prior to deployment, which exposes the cerebral vascular to embolic showers; they are not always easy to advance, deploy, and remove through a tight stenosis and/or a severely angulated vasculature; and finally, they only filter particles larger than the filter pore size, typically 100 to 120 μm. Also, these devices do not filter 100% of the flow due to incomplete wall opposition of the filter, and furthermore there is a risk of debris escape during filter retrieval.
Of particular interest to the present disclosure, an alternative method for reducing the risk of emboli release into the internal carotid artery ICA has been proposed for use during carotid stenting CAS procedures utilizing the concept of reversing the flow in the internal carotid artery ICA to prevent embolic debris entering the cerebral vasculature. Although a number of specific protocols have been described, they generally rely on placing a sheath via the femoral artery (transfemoral access) into the common carotid artery. Flow in the common carotid artery is occluded, typically by inflating a balloon on the distal tip of the sheath. Flow into the external carotid artery ECA may also be occluded, typically using a balloon catheter or balloon guidewire introduced through the sheath. The sheath is then connected to a venous location or to a low pressure external receptacle in order to establish a reverse or retrograde flow from the internal carotid artery through the sheath and away from the cerebral vasculature. After such reverse or retrograde flow is established, the stenting procedure may be performed with a greatly reduced risk of emboli entering the cerebral vasculature.
An alternate system which simply halts forward flow in the ICA consists of a carotid access sheath with two integral balloons: an ECA occlusion balloon at the distal tip, and a CCA occlusion balloon placed some fixed distance proximal to the ECA balloon. Between the two balloons is an opening for delivery of the interventional carotid stenting devices. This system does not reverse flow from the ICA to the venous system, but instead relies on blocking flow and performing aspiration to remove embolic debris prior to establishing forward flow in the ICA.
While such reverse or static flow protocols for performing stenting and other interventional procedures in the carotid vasculature hold great promise, such methods have generally required the manipulation of multiple separate access and occlusion components. Moreover, the protocols have been rather complicated, requiring many separate steps, limiting their performance to only the most skilled vascular surgeons, interventional radiologists and cardiologists. In addition, due to the size limitations of the femoral access, the access devices themselves provide a very high resistance to flow, limiting the amount of reverse flow and/or aspiration possible. Furthermore, the requirement to occlude the external carotid artery adds risk and complexity to the procedure. The balloon catheter for occluding the external carotid artery can become trapped in the arterial wall in cases where the stent is placed across the bifurcation from the common carotid artery to the internal carotid artery, and may cause damage to the deployed stent when it is removed.
None of the cerebral protection devices and methods described offer protection after the procedure. However, generation of embolic particles have been measured up to 48 hours or later, after the stent procedure. During CEA, flushing at the end of the procedure while blocking flow to the internal carotid artery ICA may help reduce post-procedure emboli generation. A similar flushing step during CAS may also reduce emboli risk. Additionally, a stent which is designed to improve entrapment of embolic particles may also reduce post-procedure emboli.
In addition, all currently available carotid stenting and cerebral protection systems are designed for access from the femoral artery. Unfortunately, the pathway from the femoral artery to the common carotid artery is relatively long, has several turns which in some patients can be quite angulated, and often contains plaque and other diseases. The portion of the procedure involving access to the common carotid artery from the femoral artery can be difficult and time consuming as well as risk generating showers of embolic debris up both the target and the opposite common carotid artery and thence to the cerebral vasculature. Some studies suggest that up to half, or more, of embolic complications during CAS procedures occur during access to the CCA. None of the protocols or systems offer protection during this portion of the procedure.
Recently, a reverse flow protocol having an alternative access route to the carotid arteries has been proposed by Criado. This alternative route consists of direct surgical access to the common carotid artery CCA, called transcervical access. Transcervical access greatly shortens the length and tortuosity of the pathway from the vascular access point to the target treatment site thereby easing the time and difficulty of the procedure. Additionally, this access route reduces the risk of emboli generation from navigation of diseased, angulated, or tortuous aortic arch or common carotid artery anatomy.
The Criado protocol is described in several publications in the medical literature cited below. As shown in
While a significant improvement over the femoral access-based retrograde flow protocols, the Criado protocol and flow shunt could still benefit from improvement. In particular, the existing arterial and venous sheaths used in the procedure still have significant flow restrictions in the side arms 214 and stopcocks 216. When an interventional catheter is inserted into the arterial access sheath, the reverse flow circuit resistance is at a maximum. In some percentage of patients, the external carotid artery ECA perfusion pressure is greater than the internal carotid artery ICA perfusion pressure. In these patients, this differential pressure might drive antegrade flow into the ICA from the ECA. A reverse flow shunt with lower flow resistance could guarantee reversal of flow in both the ECA and ICA despite a pressure gradient from the ECA to the ICA.
In addition, there is no means to monitor or regulate the reverse flow rate. The ability to increase and/or modulate the flow rate would give the user the ability to set the reverse flow rate optimally to the tolerance and physiology of the patient and the stage of the procedure, and thus offer improved protection from embolic debris. Further, the system as described by Criado relies on manually turning one or more stopcocks to open and close the reverse flow shunt, for example during injection of contrast medium to facilitate placement of the CAS systems. Finally, the Criado protocol relies on open surgical occlusion of the common carotid artery, via a vessel loop or Rummel tourniquet. A system with means to occlude the common carotid artery intravascularly, for example with an occlusion element on the arterial access sheath, would allow the entire procedure to be performed using percutaneous techniques. A percutaneous approach would limit the size and associated complications of a surgical incision, as well as enable non-surgical physicians to perform the procedure.
For these reasons, it would be desirable to provide improved methods, apparatus, and systems for performing transcervical access, retrograde flow and flushing procedures and implantation of a carotid stent in the carotid arterial vasculature to reduce the risk of procedural and post-procedural emboli, to improve the level of hemostasis throughout the procedure, and to improve the ease and speed of carotid artery stenting. The methods, apparatus, and system should simplify the procedure to be performed by the physician as well as reduce the risk of improperly performing the procedures and/or achieving insufficient retrograde flow and flushing to protect against emboli release. The systems should provide individual devices and components which are readily used with each other and which protect against emboli-related complications. The methods and systems should also provide for convenient and preferably automatic closure of any and all arterial penetrations at the end of the procedure to prevent unintended blood loss. Additionally, the systems, apparatus, and methods should be suitable for performance by either open surgical or percutaneous access routes into the vasculature. Additionally, the methods, apparatus, and systems should enable implantation of an intravascular prosthetic implant which lowers post procedural complications. At least some of these objectives will be met by the inventions described herein below.
The disclosed methods, apparatus, and systems establish and facilitate retrograde or reverse flow blood circulation in the region of the carotid artery bifurcation in order to limit or prevent the release of emboli into the cerebral vasculature, particularly into the internal carotid artery. The methods are particularly useful for interventional procedures, such as stenting and angioplasty, atherectomy, performed through a transcervical approach or transfemoral into the common carotid artery, either using an open surgical technique or using a percutaneous technique, such as a modified Seldinger technique.
Access into the common carotid artery is established by placing a sheath or other tubular access cannula into a lumen of the artery, typically having a distal end of the sheath positioned proximal to the junction or bifurcation B (
Retrograde flow is established and modulated to meet the patient's requirements. Flow through the common carotid artery is occluded, either with an external vessel loop or tape, a vascular clamp, an internal occlusion member such as a balloon, or other type of occlusion means. When flow through the common carotid artery is blocked, the natural pressure gradient between the internal carotid artery and the venous system will cause blood to flow in a retrograde or reverse direction from the cerebral vasculature through the internal carotid artery and through the shunt into the venous system.
Alternately, the venous sheath could be eliminated and the arterial sheath could be connected to an external collection reservoir or receptacle. The reverse flow could be collected in this receptacle. If desired, the collected blood could be filtered and subsequently returned to the patient during or at the end of the procedure. The pressure of the receptacle could be open to zero pressure, causing the pressure gradient to create blood to flow in a reverse direction from the cerebral vasculature to the receptacle or the pressure of the receptacle could be a negative pressure.
Optionally, to achieve or enhance reverse flow from the internal carotid artery, flow from the external carotid artery may be blocked, typically by deploying a balloon or other occlusion element in the external carotid just above (i.e., distal) the bifurcation within the internal carotid artery.
Although the procedures and protocols described hereinafter will be particularly directed at carotid stenting, it will be appreciated that the methods for accessing the carotid artery described herein would also be useful for angioplasty, artherectomy, and any other interventional procedures which might be carried out in the carotid arterial system, particularly at a location near the bifurcation between the internal and external carotid arteries. In addition, it will be appreciated that some of these access, vascular closure, and embolic protection methods will be applicable in other vascular interventional procedures, for example the treatment of acute stroke.
The present disclosure includes a number of specific aspects for improving the performance of carotid artery access protocols. At least most of these individual aspects and improvements can be performed individually or in combination with one or more other of the improvements in order to facilitate and enhance the performance of the particular interventions in the carotid arterial system.
In one aspect, there is disclosed a system for use in accessing and treating a carotid artery, said system. The system comprises an arterial access device adapted to be introduced into a common carotid artery and receive blood flow from the common carotid artery; a shunt fluidly connected to the arterial access device, wherein the shunt provides a pathway for blood to flow from the arterial access device to a return site; and a flow control assembly coupled to the shunt and adapted to regulate blood flow through the shunt between at least a first blood flow state and at least a second blood flow state, wherein the flow control assembly includes one or more components that interact with the blood flow through the shunt.
In another aspect, there is disclosed a system for use in accessing and treating a carotid artery. The system comprises an arterial access device adapted to be introduced into a common carotid artery and receive blood flow from the common carotid artery; a shunt fluidly connected to the arterial access device, wherein the shunt provides a pathway for blood to flow from the arterial access device to a return site; a flow mechanism coupled to the shunt and adapted to vary the blood flow through the shunt between a first blood flow rate and a second blood flow rate; and a controller that automatically interacts with the flow mechanism to regulate blood flow through the shunt between the first blood flow rate and the second blood flow rate without requiring input from a user.
In another aspect, there is disclosed a device for use in accessing and treating a carotid artery. The device comprises a distal sheath having a distal end adapted to be introduced into the common carotid artery, a proximal end, and a lumen extending between the distal and proximal ends; a proximal extension having a distal end, a proximal end, and a lumen therebetween, wherein the distal end of the proximal extension is connected to the proximal end of the sheath at a junction so that the lumens of each are contiguous; a flow line having a lumen, said flow line connected near the junction so that blood flowing into the distal end of the sheath can flow into the lumen of the flow line; and a hemostasis valve at the proximal end of the proximal extension, said hemostasis valve being adapted to inhibit blood flow from the proximal extension while allowing catheter introduction through the proximal extension and into the distal sheath.
In another aspect, there is disclosed a method for accessing and treating a carotid artery. The method comprises forming a penetration in a wall of a common carotid artery; positioning an access sheath through the penetration; blocking blood flow from the common carotid artery past the sheath; allowing retrograde blood flow from the carotid artery into the sheath and from the sheath via a flow path to a return site; and modifying blood flow through the flow path based on feedback data.
In another aspect, there is disclosed a method for accessing and treating a carotid artery. The method comprises forming a penetration in a wall of a common carotid artery; positioning an access sheath through the penetration; blocking blood flow from the common carotid artery past the sheath; allowing retrograde blood flow from the carotid artery into the sheath and from the sheath via a flow path to a return site; and monitoring flow through the flow path.
In another aspect, there is disclosed a method for accessing and treating a carotid artery. The method comprises: forming a penetration in a wall of a common carotid artery; positioning an arterial access sheath through the penetration; blocking blood flow from the common carotid artery past the sheath; allowing retrograde blood flow from the internal carotid artery into the sheath while the common carotid artery remains blocked; and adjusting the state of retrograde blood flow through the sheath.
In another aspect, there is disclosed a method for accessing and treating a carotid artery. The method comprises forming a penetration in a wall of a common carotid artery; positioning an arterial access sheath through the penetration; blocking blood flow from the common carotid artery past the sheath; allowing retrograde blood flow from the internal carotid artery into the sheath while the common carotid artery remains blocked; and adjusting a rate of retrograde blood flow from the sheath to as high a level as the patient will tolerate, wherein said adjusted rate is a baseline.
Other features and advantages should be apparent from the following description of various embodiments, which illustrate, by way of example, the principles of the invention.
In the embodiment of
In another embodiment, shown in
In another embodiment, shown in
With reference to the enlarged view of the carotid artery in
Description of Anatomy
Collateral Brain Circulation
The Circle of Willis CW is the main arterial anastomatic trunk of the brain where all major arteries which supply the brain, namely the two internal carotid arteries (ICAs) and the vertebral basilar system, connect. The blood is carried from the Circle of Willis by the anterior, middle and posterior cerebral arteries to the brain. This communication between arteries makes collateral circulation through the brain possible. Blood flow through alternate routes is made possible thereby providing a safety mechanism in case of blockage to one or more vessels providing blood to the brain. The brain can continue receiving adequate blood supply in most instances even when there is a blockage somewhere in the arterial system (e.g., when the ICA is ligated as described herein). Flow through the Circle of Willis ensures adequate cerebral blood flow by numerous pathways that redistribute blood to the deprived side.
The collateral potential of the Circle of Willis is believed to be dependent on the presence and size of its component vessels. It should be appreciated that considerable anatomic variation between individuals can exist in these vessels and that many of the involved vessels may be diseased. For example, some people lack one of the communicating arteries. If a blockage develops in such people, collateral circulation is compromised resulting in an ischemic event and potentially brain damage. In addition, an autoregulatory response to decreased perfusion pressure can include enlargement of the collateral arteries, such as the communicating arteries, in the Circle of Willis. An adjustment time is occasionally required for this compensation mechanism before collateral circulation can reach a level that supports normal function. This autoregulatory response can occur over the space of 15 to 30 seconds and can only compensate within a certain range of pressure and flow drop. Thus, it is possible for a transient ischemic attack to occur during the adjustment period. Very high retrograde flow rate for an extended period of time can lead to conditions where the patient's brain is not getting enough blood flow, leading to patient intolerance as exhibited by neurologic symptoms or in some cases a transient ischemic attack.
Anteriorly, the Circle of Willis is formed by the anterior cerebral arteries ACA and the anterior communicating artery ACoA which connects the two ACAs. The two posterior communicating arteries PCoA connect the Circle of Willis to the two posterior cerebral arteries PCA, which branch from the basilar artery BA and complete the Circle posteriorly.
The common carotid artery CCA also gives rise to external carotid artery ECA, which branches extensively to supply most of the structures of the head except the brain and the contents of the orbit. The ECA also helps supply structures in the neck and face.
Carotid Artery Bifurcation
As discussed above, the arterial access device 110 can access the common carotid artery CCA via a transcervical approach. Pursuant to the transcervical approach, the arterial access device 110 is inserted into the common carotid artery CCA at an arterial access location L, which can be, for example, a surgical incision or puncture in the wall of the common carotid artery CCA. There is typically a distance D of around 5 to 7 cm between the arterial access location L and the bifurcation B. When the arterial access device 110 is inserted into the common carotid artery CCA, it is undesirable for the distal tip of the arterial access device 110 to contact the bifurcation B as this could disrupt the plaque P and cause generation of embolic particles. In order to minimize the likelihood of the arterial access device 110 contacting the bifurcation B, in an embodiment only about 2-4 cm of the distal region of the arterial access device is inserted into the common carotid artery CCA during a procedure.
The common carotid arteries are encased on each side in a layer of fascia called the carotid sheath. This sheath also envelops the internal jugular vein and the vagus nerve. Anterior to the sheath is the sternocleidomastoid muscle. Transcervical access to the common carotid artery and internal jugular vein, either percutaneous or surgical, can be made immediately superior to the clavicle, between the two heads of the sternocleidomastoid muscle and through the carotid sheath, with care taken to avoid the vagus nerve.
At the upper end of this sheath, the common carotid artery bifurcates into the internal and external carotid arteries. The internal carotid artery continues upward without branching until it enters the skull to supply blood to the retina and brain. The external carotid artery branches to supply blood to the scalp, facial, ocular, and other superficial structures. Intertwined both anterior and posterior to the arteries are several facial and cranial nerves. Additional neck muscles may also overlay the bifurcation. These nerve and muscle structures can be dissected and pushed aside to access the carotid bifurcation during a carotid endarterectomy procedure. In some cases the carotid bifurcation is closer to the level of the mandible, where access is more challenging and with less room available to separate it from the various nerves which should be spared. In these instances, the risk of inadvertent nerve injury can increase and an open endarterectomy procedure may not be a good option.
Detailed Description of Retrograde Blood Flow System
As discussed, the retrograde flow system 100 includes the arterial access device 110, venous return device 115, and shunt 120 which provides a passageway for retrograde flow from the arterial access device 110 to the venous return device 115. The system also includes the flow control assembly 125, which interacts with the shunt 120 to regulate and/or monitor retrograde blood flow through the shunt 120. Exemplary embodiments of the components of the retrograde flow system 100 are now described.
Arterial Access Device
The distal sheath 605 can have a stepped or other configuration having a reduced diameter distal region 630, as shown in
With reference again to
A flush line 635 can be connected to the side of the hemostasis valve 625 and can have a stopcock 640 at its proximal or remote end. The flush-line 635 allows for the introduction of saline, contrast fluid, or the like, during the procedures. The flush line 635 can also allow pressure monitoring during the procedure. A dilator 645 having a tapered distal end 650 can be provided to facilitate introduction of the distal sheath 605 into the common carotid artery. The dilator 645 can be introduced through the hemostasis valve 625 so that the tapered distal end 650 extends through the distal end of the sheath 605, as best seen in
Optionally, a tube 705 may be provided which is coaxially received over the exterior of the distal sheath 605, also as seen in
The distal sheath 605 can be configured to establish a curved transition from a generally anterior-posterior approach over the common carotid artery to a generally axial luminal direction within the common carotid artery. The transition in direction is particularly useful when a percutaneous access is provided through the common carotid wall. While an open surgical access may allow for some distance in which to angle a straight sheath into the lumen of the common carotid artery, percutaneous access will generally be in a normal or perpendicular direction relative to the access of the lumen, and in such cases, a sheath that can flex or turn at an angle will find great use.
The sheath 605 can be formed in a variety of ways. For example, the sheath 605 can be pre-shaped to have a curve or an angle some set distance from the tip, typically 2 to 3 cm. The pre-shaped curve or angle can typically provide for a turn in the range from 20° to 90°, preferably from 30° to 70°. For initial introduction, the sheath 605 can be straightened with an obturator or other straight or shaped instrument such as the dilator 645 placed into its lumen. After the sheath 605 has been at least partially introduced through the percutaneous or other arterial wall penetration, the obturator can be withdrawn to allow the sheath 605 to reassume its pre-shaped configuration into the arterial lumen.
Other sheath configurations include having a deflection mechanism such that the sheath can be placed and the catheter can be deflected in situ to the desired deployment angle. In still other configurations, the catheter has a non-rigid configuration when placed into the lumen of the common carotid artery. Once in place, a pull wire or other stiffening mechanism can be deployed in order to shape and stiffen the sheath into its desired configuration. One particular example of such a mechanism is commonly known as “shape-lock” mechanisms as well described in medical and patent literature.
Another sheath configuration comprises a curved dilator inserted into a straight but flexible sheath, so that the dilator and sheath are curved during insertion. The sheath is flexible enough to conform to the anatomy after dilator removal.
In an embodiment, the sheath has built-in puncturing capability and atraumatic tip analogous to a guide wire tip. This eliminates the need for needle and wire exchange currently used for arterial access according to the micropuncture technique, and can thus save time, reduce blood loss, and require less surgeon skill.
As shown in
Venous Return Device
Referring now to
In order to reduce the overall system flow resistance, the arterial access flow line 615 (
The shunt 120 can be formed of a single tube or multiple, connected tubes that provide fluid communication between the arterial access catheter 110 and the venous return catheter 115 to provide a pathway for retrograde blood flow therebetween. As shown in
In an embodiment, the shunt 120 can be formed of at least one tube that communicates with the flow control assembly 125. The shunt 120 can be any structure that provides a fluid pathway for blood flow. The shunt 120 can have a single lumen or it can have multiple lumens. The shunt 120 can be removably attached to the flow control assembly 125, arterial access device 110, and/or venous return device 115. Prior to use, the user can select a shunt 120 with a length that is most appropriate for use with the arterial access location and venous return location. In an embodiment, the shunt 120 can include one or more extension tubes that can be used to vary the length of the shunt 120. The extension tubes can be modularly attached to the shunt 120 to achieve a desired length. The modular aspect of the shunt 120 permits the user to lengthen the shunt 120 as needed depending on the site of venous return. For example, in some patients, the internal jugular vein IJV is small and/or tortuous. The risk of complications at this site may be higher than at some other locations, due to proximity to other anatomic structures. In addition, hematoma in the neck may lead to airway obstruction and/or cerebral vascular complications. Consequently, for such patients it may be desirable to locate the venous return site at a location other than the internal jugular vein IJV, such as the femoral vein. A femoral vein return site may be accomplished percutaneously, with lower risk of serious complication, and also offers an alternative venous access to the central vein if the internal jugular vein IJV is not available. Furthermore, the femoral venous return changes the layout of the reverse flow shunt such that the shunt controls may be located closer to the “working area” of the intervention, where the devices are being introduced and the contrast injection port is located.
In an embodiment, the shunt 120 has an internal diameter of 4.76 mm ( 3/16 inch) and has a length of 40-70 cm. As mentioned, the length of the shunt can be adjusted.
Flow Control Assembly—Regulation and Monitoring of Retrograde Flow
The flow control assembly 125 interacts with the retrograde shunt 120 to regulate and/or monitor the retrograde flow rate from the common carotid artery to the venous return site, such as the internal jugular vein, or to the external receptacle 130. In this regard, the flow control assembly 125 enables the user to achieve higher maximum flow rates than existing systems and to also selectively adjust, set, or otherwise modulate the retrograde flow rate. Various mechanisms can be used to regulate the retrograde flow rate, as described more fully below. The flow control assembly 125 enables the user to configure retrograde blood flow in a manner that is suited for various treatment regimens, as described below.
In general, the ability to control the continuous retrograde flow rate allows the physician to adjust the protocol for individual patients and stages of the procedure. The retrograde blood flow rate will typically be controlled over a range from a low rate to a high rate. The high rate can be at least two fold higher than the low rate, typically being at least three fold higher than the low rate, and often being at least five fold higher than the low rate, or even higher. In an embodiment, the high rate is at least three fold higher than the low rate and in another embodiment the high rate is at least six fold higher than the low rate. While it is generally desirable to have a high retrograde blood flow rate to maximize the extraction of emboli from the carotid arteries, the ability of patients to tolerate retrograde blood flow will vary. Thus, by having a system and protocol which allows the retrograde blood flow rate to be easily modulated, the treating physician can determine when the flow rate exceeds the tolerable level for that patient and set the reverse flow rate accordingly. For patients who cannot tolerate continuous high reverse flow rates, the physician can chose to turn on high flow only for brief, critical portions of the procedure when the risk of embolic debris is highest. At short intervals, for example between 15 seconds and 1 minute, patient tolerance limitations are usually not a factor.
In specific embodiments, the continuous retrograde blood flow rate can be controlled at a base line flow rate in the range from 10 ml/min to 200 ml/min, typically from 20 ml/min to 100 ml/min. These flow rates will be tolerable to the majority of patients. Although flow rate is maintained at the base line flow rate during most of the procedure, at times when the risk of emboli release is increased, the flow rate can be increased above the base line for a short duration in order to improve the ability to capture such emboli. For example, the retrograde blood flow rate can be increased above the base line when the stent catheter is being introduced, when the stent is being deployed, pre- and post-dilatation of the stent, removal of the common carotid artery occlusion, and the like.
The flow rate control system can be cycled between a relatively low flow rate and a relatively high flow rate in order to “flush” the carotid arteries in the region of the carotid bifurcation prior to reestablishing antegrade flow. Such cycling can be established with a high flow rate which can be approximately two to six fold greater than the low flow rate, typically being about three fold greater. The cycles can typically have a length in the range from 0.5 seconds to 10 seconds, usually from 2 seconds to 5 seconds, with the total duration of the cycling being in the range from 5 seconds to 60 seconds, usually from 10 seconds to 30 seconds.
In addition, the flow control assembly 125 can include one or more flow sensors 1135 and/or anatomical data sensors 1140 (described in detail below) for sensing one or more aspects of the retrograde flow. A filter 1145 can be positioned along the shunt 120 for removing emboli before the blood is returned to the venous return site. When the filter 1145 is positioned upstream of the controller 1130, the filter 1145 can prevent emboli from entering the controller 1145 and potentially clogging the variable flow resistance component 1125. It should be appreciated that the various components of the flow control assembly 125 (including the pump 1110, valves 1115, syringes 1120, variable resistance component 1125, sensors 1135/1140, and filter 1145) can be positioned at various locations along the shunt 120 and at various upstream or downstream locations relative to one another. The components of the flow control assembly 125 are not limited to the locations shown in
Both the variable resistance component 1125 and the pump 1110 can be coupled to the shunt 120 to control the retrograde flow rate. The variable resistance component 1125 controls the flow resistance, while the pump 1110 provides for positive displacement of the blood through the shunt 120. Thus, the pump can be activated to drive the retrograde flow rather than relying on the perfusion stump pressures of the ECA and ICA and the venous back pressure to drive the retrograde flow. The pump 1110 can be a peristaltic tube pump or any type of pump including a positive displacement pump. The pump 1110 can be activated and deactivated (either manually or automatically via the controller 1130) to selectively achieve blood displacement through the shunt 120 and to control the flow rate through the shunt 120. Displacement of the blood through the shunt 120 can also be achieved in other manners including using the aspiration syringe 1120, or a suction source such as a vacutainer, vaculock syringe, or wall suction may be used. The pump 1110 can communicate with the controller 1130.
One or more flow control valves 1115 can be positioned along the pathway of the shunt. The valve(s) can be manually actuated or automatically actuated (via the controller 1130). The flow control valves 1115 can be, for example one-way valves to prevent flow in the antegrade direction in the shunt 120, check valves, or high pressure valves which would close off the shunt 120, for example during high-pressure contrast injections (which are intended to enter the arterial vasculature in an antegrade direction).
The controller 1130 communicates with components of the system 100 including the flow control assembly 125 to enable manual and/or automatic regulation and/or monitoring of the retrograde flow through the components of the system 100 (including, for example, the shunt 120, the arterial access device 110, the venous return device 115 and the flow control assembly 125). For example, a user can actuate one or more actuators on the controller 1130 to manually control the components of the flow control assembly 125. Manual controls can include switches or dials or similar components located directly on the controller 1130 or components located remote from the controller 1130 such as a foot pedal or similar device. The controller 1130 can also automatically control the components of the system 100 without requiring input from the user. In an embodiment, the user can program software in the controller 1130 to enable such automatic control. The controller 1130 can control actuation of the mechanical portions of the flow control assembly 125. The controller 1130 can include circuitry or programming that interprets signals generated by sensors 1135/1140 such that the controller 1130 can control actuation of the flow control assembly 125 in response to such signals generated by the sensors.
The representation of the controller 1130 in
Flow State Indicator(s)
The controller 1130 can include one or more indicators that provides a visual and/or audio signal to the user regarding the state of the retrograde flow. An audio indication advantageously reminds the user of a flow state without requiring the user to visually check the flow controller 1130. The indicator(s) can include a speaker 1150 and/or a light 1155 or any other means for communicating the state of retrograde flow to the user. The controller 1130 can communicate with one or more sensors of the system to control activation of the indicator. Or, activation of the indicator can be tied directly to the user actuating one of the flow control actuators 1165. The indicator need not be a speaker or a light. The indicator could simply be a button or switch that visually indicates the state of the retrograde flow. For example, the button being in a certain state (such as a pressed or down state) may be a visual indication that the retrograde flow is in a high state. Or, a switch or dial pointing toward a particular labeled flow state may be a visual indication that the retrograde flow is in the labeled state.
The indicator can provide a signal indicative of one or more states of the retrograde flow. In an embodiment, the indicator identifies only two discrete states: a state of “high” flow rate and a state of “low” flow rate. In another embodiment, the indicator identifies more than two flow rates, including a “high” flow rate, a “medium” flow rate, and a “low” rate. The indicator can be configured to identify any quantity of discrete states of the retrograde flow or it can identify a graduated signal that corresponds to the state of the retrograde flow. In this regard, the indicator can be a digital or analog meter 1160 that indicates a value of the retrograde flow rate, such as in ml/min or any other units.
In an embodiment, the indicator is configured to indicate to the user whether the retrograde flow rate is in a state of “high” flow rate or a “low” flow rate. For example, the indicator may illuminate in a first manner (e.g., level of brightness) and/or emit a first audio signal when the flow rate is high and then change to a second manner of illumination and/or emit a second audio signal when the flow rate is low. Or, the indicator may illuminate and/or emit an audio signal only when the flow rate is high, or only when the flow rate is low. Given that some patients may be intolerant of a high flow rate or intolerant of a high flow rate beyond an extended period of time, it can be desirable that the indicator provide notification to the user when the flow rate is in the high state. This would serve as a fail safe feature.
In another embodiment, the indicator provides a signal (audio and/or visual) when the flow rate changes state, such as when the flow rate changes from high to low and/or vice-versa. In another embodiment, the indicator provides a signal when no retrograde flow is present, such as when the shunt 120 is blocked or one of the stopcocks in the shunt 120 is closed.
Flow Rate Actuators
The controller 1130 can include one or more actuators that the user can press, switch, manipulate, or otherwise actuate to regulate the retrograde flow rate and/or to monitor the flow rate. For example, the controller 1130 can include a flow control actuator 1165 (such as one or more buttons, knobs, dials, switches, etc.) that the user can actuate to cause the controller to selectively vary an aspect of the reverse flow. For example, in the illustrated embodiment, the flow control actuator 1165 is a knob that can be turned to various discrete positions each of which corresponds to the controller 1130 causing the system 100 to achieve a particular retrograde flow state. The states include, for example, (a) OFF; (b) LO-FLOW; (c) HI-FLOW; and (d) ASPIRATE. It should be appreciated that the foregoing states are merely exemplary and that different states or combinations of states can be used. The controller 1130 achieves the various retrograde flow states by interacting with one or more components of the system, including the sensor(s), valve(s), variable resistance component, and/or pump(s). It should be appreciated that the controller 1130 can also include circuitry and software that regulates the retrograde flow rate and/or monitors the flow rate such that the user wouldn't need to actively actuate the controller 1130.
The OFF state corresponds to a state where there is no retrograde blood flow through the shunt 120. When the user sets the flow control actuator 1165 to OFF, the controller 1130 causes the retrograde flow to cease, such as by shutting off valves or closing a stop cock in the shunt 120. The LO-FLOW and HI-FLOW states correspond to a low retrograde flow rate and a high retrograde flow rate, respectively. When the user sets the flow control actuator 1165 to LO-FLOW or HI-FLOW, the controller 1130 interacts with components of the flow control regulator 125 including pump(s) 1110, valve(s) 1115 and/or variable resistance component 1125 to increase or decrease the flow rate accordingly. Finally, the ASPIRATE state corresponds to opening the circuit to a suction source, for example a vacutainer or suction unit, if active retrograde flow is desired.
The system can be used to vary the blood flow between various states including an active state, a passive state, an aspiration state, and an off state. The active state corresponds to the system using a means that actively drives retrograde blood flow. Such active means can include, for example, a pump, syringe, vacuum source, etc. The passive state corresponds to when retrograde blood flow is driven by the perfusion stump pressures of the ECA and ICA and possibly the venous pressure. The aspiration state corresponds to the system using a suction source, for example a vacutainer or suction unit, to drive retrograde blood flow. The off state corresponds to the system having zero retrograde blood flow such as the result of closing a stopcock or valve. The low and high flow rates can be either passive or active flow states. In an embodiment, the particular value (such as in ml/min) of either the low flow rate and/or the high flow rate can be predetermined and/or pre-programmed into the controller such that the user does not actually set or input the value. Rather, the user simply selects “high flow” and/or “low flow” (such as by pressing an actuator such as a button on the controller 1130) and the controller 1130 interacts with one or more of the components of the flow control assembly 125 to cause the flow rate to achieve the predetermined high or low flow rate value. In another embodiment, the user sets or inputs a value for low flow rate and/or high flow rate such as into the controller. In another embodiment, the low flow rate and/or high flow rate is not actually set. Rather, external data (such as data from the anatomical data sensor 1140) is used as the basis for affects the flow rate.
The flow control actuator 1165 can be multiple actuators, for example one actuator, such as a button or switch, to switch state from LO-FLOW to HI-FLOW and another to close the flow loop to OFF, for example during a contrast injection where the contrast is directed antegrade into the carotid artery. In an embodiment, the flow control actuator 1165 can include multiple actuators. For example, one actuator can be operated to switch flow rate from low to high, another actuator can be operated to temporarily stop flow, and a third actuator (such as a stopcock) can be operated for aspiration using a syringe. In another example, one actuator is operated to switch to LO-FLOW and another actuator is operated to switch to HI-FLOW. Or, the flow control actuator 1165 can include multiple actuators to switch states from LO-FLOW to HI-FLOW and additional actuators for fine-tuning flow rate within the high flow state and low flow state. Upon switching between LO-FLOW and HI-FLOW, these additional actuators can be used to fine-tune the flow rates within those states. Thus, it should be appreciated that within each state (i.e. high flow state and low flow states) a variety of flow rates can be dialed in and fine-tuned. A wide variety of actuators can be used to achieve control over the state of flow.
The controller 1130 or individual components of the controller 1130 can be located at various positions relative to the patient and/or relative to the other components of the system 100. For example, the flow control actuator 1165 can be located near the hemostasis valve where any interventional tools are introduced into the patient in order to facilitate access to the flow control actuator 1165 during introduction of the tools. The location may vary, for example, based on whether a transfemoral or a transcervical approach is used, as shown in
The controller 1130 and any of its components can interact with other components of the system (such as the pump(s), sensor(s), shunt, etc) in various manners. For example, any of a variety of mechanical connections can be used to enable communication between the controller 1130 and the system components. Alternately, the controller 1130 can communicate electronically or magnetically with the system components. Electro-mechanical connections can also be used. The controller 1130 can be equipped with control software that enables the controller to implement control functions with the system components. The controller itself can be a mechanical, electrical or electro-mechanical device. The controller can be mechanically, pneumatically, or hydraulically actuated or electromechanically actuated (for example in the case of solenoid actuation of flow control state). The controller 1130 can include a computer, computer processor, and memory, as well as data storage capabilities.
As mentioned, the flow control assembly 125 can include or interact with one or more sensors, which communicate with the system 100 and/or communicate with the patient's anatomy. Each of the sensors can be adapted to respond to a physical stimulus (including, for example, heat, light, sound, pressure, magnetism, motion, etc.) and to transmit a resulting signal for measurement or display or for operating the controller 1130. In an embodiment, the flow sensor 1135 interacts with the shunt 120 to sense an aspect of the flow through the shunt 120, such as flow velocity or volumetric rate of blood flow. The flow sensor 1135 could be directly coupled to a display that directly displays the value of the volumetric flow rate or the flow velocity. Or the flow sensor 1135 could feed data to the controller 1130 for display of the volumetric flow rate or the flow velocity.
The type of flow sensor 1135 can vary. The flow sensor 1135 can be a mechanical device, such as a paddle wheel, flapper valve, rolling ball, or any mechanical component that responds to the flow through the shunt 120. Movement of the mechanical device in response to flow through the shunt 120 can serve as a visual indication of fluid flow and can also be calibrated to a scale as a visual indication of fluid flow rate. The mechanical device can be coupled to an electrical component. For example, a paddle wheel can be positioned in the shunt 120 such that fluid flow causes the paddle wheel to rotate, with greater rate of fluid flow causing a greater speed of rotation of the paddle wheel. The paddle wheel can be coupled magnetically to a Hall-effect sensor to detect the speed of rotation, which is indicative of the fluid flow rate through the shunt 120.
In an embodiment, the flow sensor 1135 is an ultrasonic or electromagnetic flow meter, which allows for blood flow measurement without contacting the blood through the wall of the shunt 120. An ultrasonic or electromagnetic flow meter can be configured such that it does not have to contact the internal lumen of the shunt 120. In an embodiment, the flow sensor 1135 at least partially includes a Doppler flow meter, such as a Transonic flow meter, that measures fluid flow through the shunt 120. It should be appreciated that any of a wide variety of sensor types can be used including an ultrasound flow meter and transducer. Moreover, the system can include multiple sensors.
The system 100 is not limited to using a flow sensor 1135 that is positioned in the shunt 120 or a sensor that interacts with the venous return device 115 or the arterial access device 110. For example, an anatomical data sensor 1140 can communicate with or otherwise interact with the patient's anatomy such as the patient's neurological anatomy. In this manner, the anatomical data sensor 1140 can sense a measurable anatomical aspect that is directly or indirectly related to the rate of retrograde flow from the carotid artery. For example, the anatomical data sensor 1140 can measure blood flow conditions in the brain, for example the flow velocity in the middle cerebral artery, and communicate such conditions to a display and/or to the controller 1130 for adjustment of the retrograde flow rate based on predetermined criteria. In an embodiment, the anatomical data sensor 1140 comprises a transcranial Doppler ultrasonography (TCD), which is an ultrasound test that uses reflected sound waves to evaluate blood as it flows through the brain. Use of TCD results in a TCD signal that can be communicated to the controller 1130 for controlling the retrograde flow rate to achieve or maintain a desired TCD profile. The anatomical data sensor 1140 can be based on any physiological measurement, including reverse flow rate, blood flow through the middle cerebral artery, TCD signals of embolic particles, or other neuromonitoring signals.
In an embodiment, the system 100 comprises a closed-loop control system. In the closed-loop control system, one or more of the sensors (such as the flow sensor 1135 or the anatomical data sensor 1140) senses or monitors a predetermined aspect of the system 100 or the anatomy (such as, for example, reverse flow rate and/or neuromonitoring signal). The sensor(s) feed relevant data to the controller 1130, which continuously adjusts an aspect of the system as necessary to maintain a desired retrograde flow rate. The sensors communicate feedback on how the system 100 is operating to the controller 1130 so that the controller 1130 can translate that data and actuate the components of the flow control regulator 125 to dynamically compensate for disturbances to the retrograde flow rate. For example, the controller 1130 may include software that causes the controller 1130 to signal the components of the flow control assembly 125 to adjust the flow rate such that the flow rate is maintained at a constant state despite differing blood pressures from the patient. In this embodiment, the system 100 need not rely on the user to determine when, how long, and/or what value to set the reverse flow rate in either a high or low state. Rather, software in the controller 1130 can govern such factors. In the closed loop system, the controller 1130 can control the components of the flow control assembly 125 to establish the level or state of retrograde flow (either analog level or discreet state such as high, low, baseline, medium, etc.) based on the retrograde flow rate sensed by the sensor 1135.
In an embodiment, the anatomical data sensor 1140 (which measures a physiologic measurement in the patient) communicates a signal to the controller 1130, which adjusts the flow rate based on the signal. For example the physiological measurement may be based on flow velocity through the MCA, TCD signal, or some other cerebral vascular signal. In the case of the TCD signal, TCD may be used to monitor cerebral flow changes and to detect microemboli. The controller 1130 may adjust the flow rate to maintain the TCD signal within a desired profile. For example, the TCD signal may indicate the presence of microemboli (“TCD hits”) and the controller 1130 can adjust the retrograde flow rate to maintain the TCD hits below a threshold value of hits. (See, Ribo, et al., “Transcranial Doppler Monitoring of Transcervical Carotid Stenting with Flow Reversal Protection: A Novel Carotid Revascularization Technique”, Stroke 2006, 37, 2846-2849; Shekel, et al., “Experience of 500 Cases of Neurophysiological Monitoring in Carotid Endarterectomy”, Acta Neurochir, 2007, 149:681-689, which are incorporated by reference in their entirety.
In the case of the MCA flow, the controller 1130 can set the retrograde flow rate at the “maximum” flow rate that is tolerated by the patient, as assessed by perfusion to the brain. The controller 1130 can thus control the reverse flow rate to optimize the level of protection for the patient without relying on the user to intercede. In another embodiment, the feedback is based on a state of the devices in the system 100 or the interventional tools being used. For example, a sensor may notify the controller 1130 when the system 100 is in a high risk state, such as when an interventional catheter is positioned in the sheath 605. The controller 1130 then adjusts the flow rate to compensate for such a state.
The controller 1130 can be used to selectively augment the retrograde flow in a variety of manners. For example, it has been observed that greater reverse flow rates may cause a resultant greater drop in blood flow to the brain, most importantly the ipsilateral MCA, which may not be compensated enough with collateral flow from the Circle of Willis. Thus a higher reverse flow rate for an extended period of time may lead to conditions where the patient's brain is not getting enough blood flow, leading to patient intolerance as exhibited by neurologic symptoms. Studies show that MCA blood velocity less than 10 cm/sec is a threshold value below which patient is at risk for neurological blood deficit. There are other markers for monitoring adequate perfusion to the brains, such as EEG signals. However, a high flow rate may be tolerated even up to a complete stoppage of MCA flow for a short period, up to about 15 seconds to 1 minute.
Thus, the controller 1130 can optimize embolic debris capture by automatically increasing the reverse flow only during limited time periods which correspond to periods of heightened risk of emboli generation during a procedure. These periods of heightened risk include the period of time while an interventional device (such as a dilatation balloon for pre or post stenting dilatation or a stent delivery device) crosses the plaque P. Another period is during an interventional maneuver such as deployment of the stent or inflation and deflation of the balloon pre- or post-dilatation. A third period is during injection of contrast for angiographic imaging of treatment area. During lower risk periods, the controller can cause the reverse flow rate to revert to a lower, baseline level. This lower level may correspond to a low reverse flow rate in the ICA, or even slight antegrade flow in those patients with a high ECA to ICA perfusion pressure ratio.
In a flow regulation system where the user manually sets the state of flow, there is risk that the user may not pay attention to the state of retrograde flow (high or low) and accidentally keep the circuit on high flow. This may then lead to adverse patient reactions. In an embodiment, as a safety mechanism, the default flow rate is the low flow rate. This serves as a fail safe measure for patient's that are intolerant of a high flow rate. In this regard, the controller 1130 can be biased toward the default rate such that the controller causes the system to revert to the low flow rate after passage of a predetermined period of time of high flow rate. The bias toward low flow rate can be achieved via electronics or software, or it can be achieved using mechanical components, or a combination thereof. In an embodiment, the flow control actuator 1165 of the controller 1130 and/or valve(s) 1115 and/or pump(s) 1110 of the flow control regulator 125 are spring loaded toward a state that achieves a low flow rate. The controller 1130 is configured such that the user may over-ride the controller 1130 such as to manually cause the system to revert to a state of low flow rate if desired.
In another safety mechanism, the controller 1130 includes a timer 1170 (
In an exemplary procedure, embolic debris capture is optimized while not causing patient tolerance issues by initially setting the level of retrograde flow at a low rate, and then switching to a high rate for discreet periods of time during critical stages in the procedure. Alternately, the flow rate is initially set at a high rate, and then verifying patient tolerance to that level before proceeding with the rest of the procedure. If the patient shows signs of intolerance, the retrograde flow rate is lowered. Patient tolerance may be determined automatically by the controller based on feedback from the anatomical data sensor 1140 or it may be determined by a user based on patient observation. The adjustments to the retrograde flow rate may be performed automatically by the controller or manually by the user. Alternately, the user may monitor the flow velocity through the middle cerebral artery (MCA), for example using TCD, and then to set the maximum level of reverse flow which keeps the MCA flow velocity above the threshold level. In this situation, the entire procedure may be done without modifying the state of flow. Adjustments may be made as needed if the MCA flow velocity changes during the course of the procedure, or the patient exhibits neurologic symptoms.
Exemplary Mechanisms to Regulate Flow
The system 100 is adapted to regulate retrograde flow in a variety of manners. Any combination of the pump 1110, valve 1115, syringe 1120, and/or variable resistance component 1125 can be manually controlled by the user or automatically controlled via the controller 1130 to adjust the retrograde flow rate. Thus, the system 100 can regulate retrograde flow in various manners, including controlling an active flow component (e.g., pump, syringe, etc.), reducing the flow restriction, switching to an aspiration source (such as a pre-set VacLock syringe, Vacutainer, suction system, or the like), or any combination thereof.
In the situation of
The variable flow resistance in shunt 120 may be provided in a wide variety of ways. In this regard, flow resistance component 1125 can cause a change in the size or shape of the shunt to vary flow conditions and thereby vary the flow rate. Or, the flow resistance component 1125 can re-route the blood flow through one or more alternate flow pathways in the shunt to vary the flow conditions. Some exemplary embodiments of the flow resistance component 1125 are now described.
As shown in
Rather than using an inflatable internal bladder, as shown in
Referring now to
Referring now to
As yet another alternative, the flow resistance through shunt 120 may be changed by providing two or more alternative flow paths. As shown in
The shunt 120 can also be arranged in a variety of coiled configurations which permit external compression to vary the flow resistance in a variety of ways. Arrangement of a portion of the shunt 120 in a coil contains a long section of the shunt in a relatively small area. This allows compression of a long length of the shunt 120 over a small space. As shown in
A similar compression apparatus is shown in
As shown in
The dowel 2040 enters the internal lumen 2035 via a hemostasis valve in the housing 2030. A cap 2050 and an O-ring 2055 provide a sealing engagement that seals the housing 2030 and dowel 2040 against leakage. The cap 2050 may have a locking feature, such as threads, that can be used to lock the cap 2050 against the housing 2030 and to also fix the position of the dowel 2040 in the housing 2040. When the cap 2050 is locked or tightened, the cap 2050 exerts pressure against the O-ring 2055 to tighten it against the dowel 2040 in a sealed engagement. When the cap 2050 is unlocked or untightened, the dowel 2040 is free to move in and out of the housing 2030.
Exemplary Methods of Use
Referring now to
The venous return device 115 is then inserted into a venous return site, such as the internal jugular vein IJV (not shown in
Once all components of the system are in place and connected, flow through the common carotid artery CCA is stopped, typically using the occlusion element 129 as shown in
At that point retrograde flow RG from the external carotid artery ECA and internal carotid artery ICA will begin and will flow through the sheath 605, the flow line 615, the shunt 120, and into the venous return device 115 via the flow line 915. The flow control assembly 125 regulates the retrograde flow as described above.
The rate of retrograde flow can be increased during periods of higher risk for emboli generation for example while the stent delivery catheter 2110 is being introduced and optionally while the stent 2115 is being deployed. The rate of retrograde flow can be increased also during placement and expansion of balloons for dilatation prior to or after stent deployment. An atherectomy can also be performed before stenting under retrograde flow.
Still further optionally, after the stent 2115 has been expanded, the bifurcation B can be flushed by cycling the retrograde flow between a low flow rate and high flow rate. The region within the carotid arteries where the stent has been deployed or other procedure performed may be flushed with blood prior to reestablishing normal blood flow. In particular, while the common carotid artery remains occluded, a balloon catheter or other occlusion element may be advanced into the internal carotid artery and deployed to fully occlude that artery. The same maneuver may also be used to perform a post-deployment stent dilatation, which is typically done currently in self-expanding stent procedures. Flow from the common carotid artery and into the external carotid artery may then be reestablished by temporarily opening the occluding means present in the artery. The resulting flow will thus be able to flush the common carotid artery which saw slow, turbulent, or stagnant flow during carotid artery occlusion into the external carotid artery. In addition, the same balloon may be positioned distally of the stent during reverse flow and forward flow then established by temporarily relieving occlusion of the common carotid artery and flushing. Thus, the flushing action occurs in the stented area to help remove loose or loosely adhering embolic debris in that region.
Optionally, while flow from the common carotid artery continues and the internal carotid artery remains blocked, measures can be taken to further loosen emboli from the treated region. For example, mechanical elements may be used to clean or remove loose or loosely attached plaque or other potentially embolic debris within the stent, thrombolytic or other fluid delivery catheters may be used to clean the area, or other procedures may be performed. For example, treatment of in-stent restenosis using balloons, atherectomy, or more stents can be performed under retrograde flow In another example, the occlusion balloon catheter may include flow or aspiration lumens or channels which open proximal to the balloon. Saline, thrombolytics, or other fluids may be infused and/or blood and debris aspirated to or from the treated area without the need for an additional device. While the emboli thus released will flow into the external carotid artery, the external carotid artery is generally less sensitive to emboli release than the internal carotid artery. By prophylactically removing potential emboli which remain, when flow to the internal carotid artery is reestablished, the risk of emboli release is even further reduced. The emboli can also be released under retrograde flow so that the emboli flows through the shunt 120 to the venous system, a filter in the shunt 120, or the receptacle 130.
After the bifurcation has been cleared of emboli, the occlusion element 129 or alternately the tourniquet 2105 can be released, reestablishing antegrade flow, as shown in
A self-closing element may be deployed about the penetration in the wall of the common carotid artery prior to withdrawing the sheath 605 at the end of the procedure. Usually, the self-closing element will be deployed at or near the beginning of the procedure, but optionally, the self-closing element could be deployed as the sheath is being withdrawn, often being released from a distal end of the sheath onto the wall of the common carotid artery. Use of the self-closing element is advantageous since it affects substantially the rapid closure of the penetration in the common carotid artery as the sheath is being withdrawn. Such rapid closure can reduce or eliminate unintended blood loss either at the end of the procedure or during accidental dislodgement of the sheath. In addition, such a self-closing element may reduce the risk of arterial wall dissection during access. Further, the self-closing element may be configured to exert a frictional or other retention force on the sheath during the procedure. Such a retention force is advantageous and can reduce the chance of accidentally dislodging the sheath during the procedure. A self-closing element eliminates the need for vascular surgical closure of the artery with suture after sheath removal, reducing the need for a large surgical field and greatly reducing the surgical skill required for the procedure.
The disclosed systems and methods may employ a wide variety of self-closing elements, typically being mechanical elements which include an anchor portion and a self-closing portion. The anchor portion may comprise hooks, pins, staples, clips, tine, suture, or the like, which are engaged in the exterior surface of the common carotid artery about the penetration to immobilize the self-closing element when the penetration is fully open. The self-closing element may also include a spring-like or other self-closing portion which, upon removal of the sheath, will close the anchor portion in order to draw the tissue in the arterial wall together to provide closure. Usually, the closure will be sufficient so that no further measures need be taken to close or seal the penetration. Optionally, however, it may be desirable to provide for supplemental sealing of the self-closing element after the sheath is withdrawn. For example, the self-closing element and/or the tissue tract in the region of the element can be treated with hemostatic materials, such as bioabsorbable polymers, collagen plugs, glues, sealants, clotting factors, or other clot-promoting agents. Alternatively, the tissue or self-closing element could be sealed using other sealing protocols, such as electrocautery, suturing, clipping, stapling, or the like. In another method, the self-closing element will be a self-sealing membrane or gasket material which is attached to the outer wall of the vessel with clips, glue, bands, or other means. The self-sealing membrane may have an inner opening such as a slit or cross cut, which would be normally closed against blood pressure. Any of these self-closing elements could be designed to be placed in an open surgical procedure, or deployed percutaneously.
In another embodiment, carotid artery stenting may be performed after the sheath is placed and an occlusion balloon catheter deployed in the external carotid artery. The stent having a side hole or other element intended to not block the ostium of the external carotid artery may be delivered through the sheath with a guidewire or a shaft of an external carotid artery occlusion balloon received through the side hole. Thus, as the stent is advanced, typically by a catheter being introduced over a guidewire which extends into the internal carotid artery, the presence of the catheter shaft in the side hole will ensure that the side hole becomes aligned with the ostium to the external carotid artery as the stent is being advanced. When an occlusion balloon is deployed in the external carotid artery, the side hole prevents trapping the external carotid artery occlusion balloon shaft with the stent which is a disadvantage of the other flow reversal systems. This approach also avoids “jailing” the external carotid artery, and if the stent is covered with a graft material, avoids blocking flow to the external carotid artery.
In another embodiment, stents are placed which have a shape which substantially conforms to any preexisting angle between the common carotid artery and the internal carotid artery. Due to significant variation in the anatomy among patients, the bifurcation between the internal carotid artery and the external carotid artery may have a wide variety of angles and shapes. By providing a family of stents having differing geometries, or by providing individual stents which may be shaped by the physician prior to deployment, the physician may choose a stent which matches the patient's particular anatomy prior to deployment. The patient's anatomy may be determined using angiography or by other conventional means. As a still further alternative, the stent may have sections of articulation. These stents may be placed first and then articulated in situ in order to match the angle of bifurcation between a common carotid artery and internal carotid artery. Stents may be placed in the carotid arteries, where the stents have a sidewall with different density zones.
In another embodiment, a stent may be placed where the stent is at least partly covered with a graft material at either or both ends. Generally, the stent will be free from graft material and the middle section of the stent which will be deployed adjacent to the ostium to the external carotid artery to allow blood flow from the common carotid artery into the external carotid artery.
In another embodiment, a stent delivery system can be optimized for transcervical access by making them shorter and more rigid than systems designed for transfemoral access. These changes will improve the ability to torque and position the stent accurately during deployment. In addition, the stent delivery system can be designed to align the stent with the ostium of the external carotid artery, either by using the external carotid occlusion balloon or a separate guide wire in the external carotid artery, which is especially useful with stents with sideholes or for stents with curves, bends, or angulation where orientation is critical.
In certain embodiments, the shunt is fixedly connected to the arterial access sheath and the venous return sheath so that the entire assembly of the replaceable flow assembly and sheaths may be disposable and replaceable as a unit. In other instances, the flow control assembly may be removably attached to either or both of the sheaths.
In an embodiment, the user first determines whether any periods of heightened risk of emboli generation may exist during the procedure. As mentioned, some exemplary periods of heightened risk include (1) during periods when the plaque P is being crossed by a device; (2) during an interventional procedure, such as during delivery of a stent or during inflation or deflation of a balloon catheter or guidewire; (3) during injection or contrast. The foregoing are merely examples of periods of heightened risk. During such periods, the user sets the retrograde flow at a high rate for a discreet period of time. At the end of the high risk period, or if the patient exhibits any intolerance to the high flow rate, then the user reverts the flow state to baseline flow. If the system has a timer, the flow state automatically reverts to baseline flow after a set period of time. In this case, the user may re-set the flow state to high flow if the procedure is still in a period of heightened embolic risk.
In another embodiment, if the patient exhibits an intolerance to the presence of retrograde flow, then retrograde flow is established only during placement of a filter in the ICA distal to the plaque P. Retrograde flow is then ceased while an interventional procedure is performed on the plaque P. Retrograde flow is then re-established while the filter is removed. In another embodiment, a filter is places in the ICA distal of the plaque P and retrograde flow is established while the filter is in place. This embodiment combines the use of a distal filter with retrograde flow.
Although embodiments of various methods and devices are described herein in detail with reference to certain versions, it should be appreciated that other versions, embodiments, methods of use, and combinations thereof are also possible. Therefore the spirit and scope of the appended claims should not be limited to the description of the embodiments contained herein.
|Cited Patent||Filing date||Publication date||Applicant||Title|
|US4301803||28 Sep 1979||24 Nov 1981||Kuraray Co., Ltd.||Balloon catheter|
|US4771777||6 Jan 1987||20 Sep 1988||Advanced Cardiovascular Systems, Inc.||Perfusion type balloon dilatation catheter, apparatus and method|
|US4840690||10 Mar 1988||20 Jun 1989||Becton, Dickinson And Company||Method of constructing a blood flow conduit|
|US4865581||29 May 1987||12 Sep 1989||Retroperfusion Systems, Inc.||Retroperfusion control apparatus, system and method|
|US4921478||23 Feb 1988||1 May 1990||C. R. Bard, Inc.||Cerebral balloon angioplasty system|
|US4921479||2 Oct 1987||1 May 1990||Joseph Grayzel||Catheter sheath with longitudinal seam|
|US5007921||26 Oct 1989||16 Apr 1991||Brown Alan W||Surgical staple|
|US5026390||20 Sep 1990||25 Jun 1991||Brown Alan W||Surgical staple|
|US5135484||9 May 1990||4 Aug 1992||Pioneering Technologies, Inc.||Method of removing plaque from vessels|
|US5163906||12 Mar 1992||17 Nov 1992||Schneider (Europe) Ag||Dilatation catheter and method for widening of strictures|
|US5250060||26 Jun 1992||5 Oct 1993||Carbo Paul L||Angioplasty apparatus|
|US5304184||19 Oct 1992||19 Apr 1994||Indiana University Foundation||Apparatus and method for positive closure of an internal tissue membrane opening|
|US5306250||2 Apr 1992||26 Apr 1994||Indiana University Foundation||Method and apparatus for intravascular drug delivery|
|US5312356||22 May 1990||17 May 1994||Target Therapeutics||Catheter with low-friction distal segment|
|US5324262||9 Feb 1993||28 Jun 1994||Cathco, Inc.||Introducer sheath with expandable outer tube and method of use|
|US5328470||26 Jul 1991||12 Jul 1994||The Regents Of The University Of Michigan||Treatment of diseases by site-specific instillation of cells or site-specific transformation of cells and kits therefor|
|US5328471||4 Aug 1993||12 Jul 1994||Endoluminal Therapeutics, Inc.||Method and apparatus for treatment of focal disease in hollow tubular organs and other tissue lumens|
|US5380284||13 Aug 1993||10 Jan 1995||Don Michael; T. Anthony||Obstruction dissolution catheter with variably expanding blocking balloons and method of use|
|US5403328||3 Feb 1993||4 Apr 1995||United States Surgical Corporation||Surgical apparatus and method for suturing body tissue|
|US5429605||26 Jan 1994||4 Jul 1995||Target Therapeutics, Inc.||Microballoon catheter|
|US5437632||2 Jun 1993||1 Aug 1995||Target Therapeutics, Inc.||Variable stiffness balloon catheter|
|US5443454||9 Dec 1993||22 Aug 1995||Terumo Kabushiki Kaisha||Catheter for embolectomy|
|US5454795||27 Jun 1994||3 Oct 1995||Target Therapeutics, Inc.||Kink-free spiral-wound catheter|
|US5476450||5 Jan 1994||19 Dec 1995||Ruggio; Joseph M.||Apparatus and method for aspirating intravascular, pulmonary and cardiac obstructions|
|US5476469||9 Feb 1994||19 Dec 1995||Indiana University Foundation||Apparatus and method for positive closure of an internal tissue membrane opening|
|US5484412||19 Apr 1994||16 Jan 1996||Pierpont; Brien E.||Angioplasty method and means for performing angioplasty|
|US5484418||2 Nov 1994||16 Jan 1996||Endovascular Technologies, Inc.||Dual valve reinforced sheath and method|
|US5492530||2 Feb 1995||20 Feb 1996||Cathco, Inc.||Method for accessing the coronary arteries from the radial or brachial artery in the arm|
|US5496294||8 Jul 1994||5 Mar 1996||Target Therapeutics, Inc.||Catheter with kink-resistant distal tip|
|US5520702||24 Feb 1994||28 May 1996||United States Surgical Corporation||Method and apparatus for applying a cinch member to the ends of a suture|
|US5527322||8 Nov 1993||18 Jun 1996||Perclose, Inc.||Device and method for suturing of internal puncture sites|
|US5542937||24 Jun 1994||6 Aug 1996||Target Therapeutics, Inc.||Multilumen extruded catheter|
|US5549633||24 Aug 1994||27 Aug 1996||Kensey Nash Corporation||Apparatus and methods of use for preventing blood seepage at a percutaneous puncture site|
|US5558635||6 Dec 1994||24 Sep 1996||Medtronic, Inc.||Exchangeable guide system|
|US5573520||26 Oct 1994||12 Nov 1996||Mayo Foundation For Medical Education And Research||Flexible tubular device for use in medical applications|
|US5584803 *||28 Jul 1994||17 Dec 1996||Heartport, Inc.||System for cardiac procedures|
|US5599326||20 Dec 1994||4 Feb 1997||Target Therapeutics, Inc.||Catheter with multi-layer section|
|US5613974||1 Jun 1994||25 Mar 1997||Perclose, Inc.||Apparatus and method for vascular closure|
|US5628754||1 Aug 1995||13 May 1997||Medtronic, Inc.||Stent delivery guide catheter|
|US5643289||16 Aug 1995||1 Jul 1997||Lasersurge, Inc.||Surgical crimping device and method of use|
|US5643292||10 Jan 1995||1 Jul 1997||Applied Medical Resources Corporation||Percutaneous suturing device|
|US5649959||10 Feb 1995||22 Jul 1997||Sherwood Medical Company||Assembly for sealing a puncture in a vessel|
|US5658264||10 Nov 1994||19 Aug 1997||Target Therapeutics, Inc.||High performance spiral-wound catheter|
|US5667499||4 Oct 1994||16 Sep 1997||Scimed Life Systems, Inc.||Guide catheter unibody|
|US5669917||12 May 1995||23 Sep 1997||Lasersurge, Inc.||Surgical crimping device and method of use|
|US5674231||20 Oct 1995||7 Oct 1997||United States Surgical Corporation||Apparatus and method for vascular hole closure|
|US5695483||17 Aug 1995||9 Dec 1997||Target Therapeutics Inc.||Kink-free spiral-wound catheter|
|US5702373||31 Aug 1995||30 Dec 1997||Target Therapeutics, Inc.||Composite super-elastic alloy braid reinforced catheter|
|US5707376||7 Jun 1995||13 Jan 1998||William Cook Europe A/S||Stent introducer and method of use|
|US5720757||6 Jun 1995||24 Feb 1998||Indiana University Foundation||Apparatus and method for positive closure of an internal tissue membrane opening|
|US5730734||14 Nov 1996||24 Mar 1998||Scimed Life Systems, Inc.||Catheter systems with interchangeable parts|
|US5749849||20 May 1994||12 May 1998||Target Therapeutics, Inc.||Variable stiffness balloon catheter|
|US5749858||24 Oct 1996||12 May 1998||Schneider (Europe) A.G.||Method of using an aspiration catheter|
|US5766183||21 Oct 1996||16 Jun 1998||Lasersurge, Inc.||Vascular hole closure|
|US5769821||28 Mar 1997||23 Jun 1998||Quinton Instrument Company||Catheter tip retainer|
|US5769830 *||1 Sep 1994||23 Jun 1998||Cook Incorporated||Soft tip guiding catheter|
|US5779719||14 Jun 1994||14 Jul 1998||Perclose, Inc.||Device and method for the percutaneous suturing of a vascular puncture site|
|US5782800||17 Dec 1996||21 Jul 1998||Yoon; Inbae||Expandable multifunctional manipulating instruments for various medical procedures and methods therefor|
|US5792152||26 Apr 1996||11 Aug 1998||Perclose, Inc.||Device and method for suturing of internal puncture sites|
|US5795341||7 Jun 1995||18 Aug 1998||Target Therapeutics, Inc.||High performance spiral-wound catheter|
|US5797929||2 Nov 1995||25 Aug 1998||Perclose, Inc.||Apparatus and methods for advancing surgical knots|
|US5810846||3 Aug 1995||22 Sep 1998||United States Surgical Corporation||Vascular hole closure|
|US5810850||23 Sep 1997||22 Sep 1998||Indiana University Foundation||Apparatus and method for positive closure of an internal tissue membrane opening|
|US5810869||18 Nov 1996||22 Sep 1998||Localmed, Inc.||Methods for loading coaxial catheters|
|US5827229||24 May 1995||27 Oct 1998||Boston Scientific Corporation Northwest Technology Center, Inc.||Percutaneous aspiration thrombectomy catheter system|
|US5833650||5 Jun 1995||10 Nov 1998||Percusurge, Inc.||Catheter apparatus and method for treating occluded vessels|
|US5836926||13 May 1996||17 Nov 1998||Schneider (Usa) Inc||Intravascular catheter|
|US5846251||22 Jul 1996||8 Dec 1998||Hart; Charles C.||Access device with expandable containment member|
|US5851210||21 Mar 1997||22 Dec 1998||Torossian; Richard||Stent delivery system and method|
|US5853400||3 Jun 1997||29 Dec 1998||Target Therapeutics, Inc.||High performance spiral-wound catheter|
|US5860990||23 Aug 1996||19 Jan 1999||Nr Medical, Inc.||Method and apparatus for suturing|
|US5860991||22 Aug 1997||19 Jan 1999||Perclose, Inc.||Method for the percutaneous suturing of a vascular puncture site|
|US5876367||5 Dec 1996||2 Mar 1999||Embol-X, Inc.||Cerebral protection during carotid endarterectomy and downstream vascular protection during other surgeries|
|US5876386||1 Jul 1997||2 Mar 1999||Target Therapeutics, Inc.||Kink-free spiral-wound catheter|
|US5882334||4 Dec 1995||16 Mar 1999||Target Therapeutics, Inc.||Balloon/delivery catheter assembly with adjustable balloon positioning|
|US5895399||9 Oct 1996||20 Apr 1999||Embol-X Inc.||Atherectomy device having trapping and excising means for removal of plaque from the aorta and other arteries|
|US5910154||12 Feb 1998||8 Jun 1999||Embol-X, Inc.||Percutaneous catheter and guidewire having filter and medical device deployment|
|US5913848||6 Jun 1996||22 Jun 1999||Luther Medical Products, Inc.||Hard tip over-the-needle catheter and method of manufacturing the same|
|US5916208||21 Nov 1996||29 Jun 1999||Luther Medical Products, Inc.||Hard tip over-the-needle catheter and method of manufacturing the same|
|US5921952||14 Aug 1997||13 Jul 1999||Boston Scientific Corporation||Drainage catheter delivery system|
|US5921994||7 Oct 1997||13 Jul 1999||Perclose, Inc.||Low profile intraluminal suturing device and method|
|US5935122||1 Aug 1997||10 Aug 1999||Endovascular Technologies, Inc.||Dual valve, flexible expandable sheath and method|
|US5938645||20 Mar 1997||17 Aug 1999||Boston Scientific Corporation Northwest Technology Center Inc.||Percutaneous aspiration catheter system|
|US5976093||7 Apr 1994||2 Nov 1999||Cardiovascular Imaging Systems, Inc.||Vascular catheter having low-profile distal end|
|US5997508||28 Mar 1996||7 Dec 1999||Medtronic, Inc.||Expandable percutaneous introducer sheath|
|US6004310||17 Jun 1998||21 Dec 1999||Target Therapeutics, Inc.||Multilumen catheter shaft with reinforcement|
|US6004341||5 Dec 1996||21 Dec 1999||Loma Linda University Medical Center||Vascular wound closure device|
|US6022340||12 Jun 1998||8 Feb 2000||Target Therapeutics Inc.||Ballon/delivery catheter assembly with adjustable balloOn positioning|
|US6030369||3 Jul 1997||29 Feb 2000||Target Therapeutics Inc.||Micro catheter shaft|
|US6030395||28 May 1999||29 Feb 2000||Kensey Nash Corporation||Anastomosis connection system|
|US6033388||10 Apr 1998||7 Mar 2000||Medtronic Ave, Inc.||Catheter introducer with thin walled sheath|
|US6042601||18 Mar 1998||28 Mar 2000||United States Surgical Corporation||Apparatus for vascular hole closure|
|US6053903||6 Oct 1998||25 Apr 2000||Target Therapeutics, Inc.||High performance spiral-wound catheter|
|US6053904||5 Apr 1996||25 Apr 2000||Robert M. Scribner||Thin wall catheter introducer system|
|US6071263||7 Jun 1995||6 Jun 2000||Kirkman; Thomas R.||Apparatus and method for retaining a catheter in a blood vessel in a fixed position|
|US6074398||13 Jan 1998||13 Jun 2000||Datascope Investment Corp.||Reduced diameter stent/graft deployment catheter|
|US6090072||14 Mar 1996||18 Jul 2000||Scimed Life Systems, Inc.||Expandable introducer sheath|
|US6110185||19 Jan 1999||29 Aug 2000||Medtronic, Inc.||Cannula having integral suture tourniquet|
|US6117144||14 Jan 1999||12 Sep 2000||Sutura, Inc.||Suturing device and method for sealing an opening in a blood vessel or other biological structure|
|US6117145||16 Oct 1997||12 Sep 2000||Perclose, Inc.||Method and device for providing hemostasis at vascular penetration sites|
|US6132440||22 Sep 1998||17 Oct 2000||Advanced Research & Technology Institute||Apparatus and method for positive closure of an internal tissue membrane opening|
|US6136010||4 Mar 1999||24 Oct 2000||Perclose, Inc.||Articulating suturing device and method|
|US6139524||16 Oct 1998||31 Oct 2000||Scimed Life Systems, Inc.||Stent delivery system with perfusion|
|US6146370||7 Apr 1999||14 Nov 2000||Coaxia, Inc.||Devices and methods for preventing distal embolization from the internal carotid artery using flow reversal by partial occlusion of the external carotid artery|
|US6146373||17 Oct 1997||14 Nov 2000||Micro Therapeutics, Inc.||Catheter system and method for injection of a liquid embolic composition and a solidification agent|
|US6146415||7 May 1999||14 Nov 2000||Advanced Cardiovascular Systems, Inc.||Stent delivery system|
|US6152912||10 Jun 1997||28 Nov 2000||Target Therapeutics, Inc.||Optimized high performance spiral-wound vascular catheter|
|US6159230||28 May 1999||12 Dec 2000||Samuels; Shaun L. W.||Expandable lumen device and method of use|
|US6161547||15 Jan 1999||19 Dec 2000||Coaxia, Inc.||Medical device for flow augmentation in patients with occlusive cerebrovascular disease and methods of use|
|US6165199||12 Jan 1999||26 Dec 2000||Coaxia, Inc.||Medical device for removing thromboembolic material from cerebral arteries and methods of use|
|US6176844||18 May 1998||23 Jan 2001||Peter Y. Lee||Catheter system for the isolation of a segment of blood vessel|
|US6190396||14 Sep 1999||20 Feb 2001||Perclose, Inc.||Device and method for deploying and organizing sutures for anastomotic and other attachments|
|US6197016||6 Jul 1999||6 Mar 2001||Endovascular Technologies, Inc.||Dual valve, flexible expandable sheath and method|
|US6197042||5 Jan 2000||6 Mar 2001||Medical Technology Group, Inc.||Vascular sheath with puncture site closure apparatus and methods of use|
|US6206868||14 Jun 1999||27 Mar 2001||Arteria Medical Science, Inc.||Protective device and method against embolization during treatment of carotid artery disease|
|US6206893||8 Apr 1998||27 Mar 2001||Perclose, Inc.||Device and method for suturing of internal puncture sites|
|US6210370||10 Jan 1997||3 Apr 2001||Applied Medical Resources Corporation||Access device with expandable containment member|
|US6234971||13 Jul 1999||22 May 2001||Cardiovascular Imaging Systems, Inc.||Vascular catheter having low-profile distal end|
|US6245079||23 Dec 1999||12 Jun 2001||Sutura, Inc.||Suturing device and method for sealing an opening in a blood vessel or other biological structure|
|US6258080||18 Nov 1998||10 Jul 2001||Target Therapeutics, Inc.||Kink-free spiral-wound catheter|
|US6258115||21 Apr 1998||10 Jul 2001||Artemis Medical, Inc.||Bifurcated stent and distal protection system|
|US6270477||6 Mar 1997||7 Aug 2001||Percusurge, Inc.||Catheter for emboli containment|
|US6277140||16 Jan 2001||21 Aug 2001||Integrated Vascular Systems, Inc.||Vascular sheath with puncture site closure apparatus and methods of use|
|US6287319||30 Mar 1999||11 Sep 2001||Amed Systems, Inc.||Cannula with balloon tip|
|US6295989||4 Feb 1998||2 Oct 2001||Arteria Medical Science, Inc.||ICA angioplasty with cerebral protection|
|US6302898||10 Feb 1998||16 Oct 2001||Advanced Closure Systems, Inc.||Devices for sealing punctures in body vessels|
|US6306106||19 Jun 2000||23 Oct 2001||Advanced Cardiovascular Systems, Inc.||Diagnostic sheath for reduced embolic risk|
|US6306163||4 Aug 1998||23 Oct 2001||Advanced Cardiovascular Systems, Inc.||Assembly for collecting emboli and method of use|
|US6312444||12 Apr 2000||6 Nov 2001||Coaxia, Inc.||Medical device for removing thromboembolic material from cerebral arteries and methods of use|
|US6348059||20 Apr 2000||19 Feb 2002||Advanced Research & Technology Institute, Inc.||Apparatus and method for positive closure of an internal tissue membrane opening|
|US6355050||26 Jun 1997||12 Mar 2002||Abbott Laboratories||Device and method for suturing tissue|
|US6358258||14 Sep 1999||19 Mar 2002||Abbott Laboratories||Device and method for performing end-to-side anastomosis|
|US6364900||14 Jul 1999||2 Apr 2002||Richard R. Heuser||Embolism prevention device|
|US6368316||11 Jun 1998||9 Apr 2002||Target Therapeutics, Inc.||Catheter with composite stiffener|
|US6368334||12 Mar 1998||9 Apr 2002||Lasersurge, Inc.||Vascular hole closure|
|US6368344||16 Dec 1999||9 Apr 2002||Advanced Cardiovascular Systems, Inc.||Stent deployment system with reinforced inner member|
|US6383172||2 Apr 1999||7 May 2002||Coaxia, Inc.||Retrograde venous perfusion with isolation of cerebral circulation|
|US6391048||5 Jul 2000||21 May 2002||Integrated Vascular Systems, Inc.||Integrated vascular device with puncture site closure component and sealant and methods of use|
|US6413235||13 May 1998||2 Jul 2002||Arteria Medical Science, Inc.||Protective device against embolization in carotid angioplasty|
|US6423032||15 Oct 1999||23 Jul 2002||Arteria Medical Science, Inc.||Apparatus and methods for reducing embolization during treatment of carotid artery disease|
|US6423086||18 Oct 2000||23 Jul 2002||Embol-X, Inc.||Cannula with associated filter and methods of use during cardiac surgery|
|US6428549||29 Aug 2000||6 Aug 2002||X-Site, L.L.C.||Device and method for suturing blood vessels and the like|
|US6454741||24 Mar 2000||24 Sep 2002||Medtronic Percusurge, Inc.||Aspiration method|
|US6458151||7 Sep 2000||1 Oct 2002||Frank S. Saltiel||Ostial stent positioning device and method|
|US6461364||11 Apr 2000||8 Oct 2002||Integrated Vascular Systems, Inc.||Vascular sheath with bioabsorbable puncture site closure apparatus and methods of use|
|US6464664||3 Nov 1999||15 Oct 2002||Medtronic, Inc.||Method for using intravascular balloon occlusion device|
|US6471672||10 Nov 1999||29 Oct 2002||Scimed Life Systems||Selective high pressure dilation balloon|
|US6482172||9 Feb 2000||19 Nov 2002||Jeffrey J. Thramann||Flow-by channel catheter and method of use|
|US6517520||21 Dec 2000||11 Feb 2003||Ethicon Endo Surgery, Inc.||Peripherally inserted catheter with flushable guide-tube|
|US6517553||24 Jan 2001||11 Feb 2003||Abbott Laboratories||Device and method for suturing of internal puncture sites|
|US6527746||3 Aug 2000||4 Mar 2003||Ev3, Inc.||Back-loading catheter|
|US6533800||25 Jul 2001||18 Mar 2003||Coaxia, Inc.||Devices and methods for preventing distal embolization using flow reversal in arteries having collateral blood flow|
|US6540712||20 Mar 2000||1 Apr 2003||Arteria Medical Science, Inc.||Methods and low profile apparatus for reducing embolization during treatment of carotid artery disease|
|US6544276||27 Mar 1998||8 Apr 2003||Medtronic Ave. Inc.||Exchange method for emboli containment|
|US6551268||14 Apr 2000||22 Apr 2003||Embol-X, Inc.||Cerebral protection during carotid endarterectomy and downstream vascular protection during other surgeries|
|US6551331||30 Jan 2001||22 Apr 2003||Sutura, Inc.||Suturing device and method for sealing an opening in a blood vessel or other biological structure|
|US6555057||14 Jan 2000||29 Apr 2003||Coaxia, Inc.||Intravascular methods and apparatus for isolation and selective cooling of the cerebral vasculature during surgical procedures|
|US6558356||25 Apr 2000||6 May 2003||Coaxia, Inc.||Medical device for flow augmentation in patients with occlusive cerebrovascular disease and methods of use|
|US6558399||30 Jun 2000||6 May 2003||Abbott Laboratories||Devices and method for handling a plurality of suture elements during a suturing procedure|
|US6562049||9 Nov 2000||13 May 2003||Cook Vascular Incorporated||Medical introducer apparatus|
|US6569182||12 Apr 2000||27 May 2003||Embol-X, Inc.||Introducer/dilator with balloon protection and methods of use|
|US6582390||8 Nov 2000||24 Jun 2003||Endovascular Technologies, Inc.||Dual lumen peel-away sheath introducer|
|US6582396||20 Mar 2000||24 Jun 2003||Arteria Medical Science, Inc.||Puncture resistant balloon for use in carotid artery procedures and methods of use|
|US6582448||21 Dec 2000||24 Jun 2003||Advanced Cardiovascular Systems, Inc.||Vessel occlusion device for embolic protection system|
|US6589206||10 Oct 2000||8 Jul 2003||Heartport, Inc.||Methods and devices for occluding the ascending aorta and maintaining circulation of oxygenated blood in the patient when the patient's heart is arrested|
|US6595953||30 Nov 1999||22 Jul 2003||Gioacchino Coppi||Endovascular system for the treatment of stenoses of the carotid and catheter for this system|
|US6595980||23 Feb 2001||22 Jul 2003||Coaxia, Inc.||Devices and methods for preventing distal embolization using flow reversal by occlusion of the brachiocephalic artery|
|US6596003||28 Jun 2000||22 Jul 2003||Genzyme Corporation||Vascular anastomosis device|
|US6605074||16 Sep 2002||12 Aug 2003||Medtronic Ave, Inc.||Method for containing and removing occlusions in the carotid arteries|
|US6612999||6 Dec 2001||2 Sep 2003||Cardiac Pacemakers, Inc.||Balloon actuated guide catheter|
|US6623471||12 Oct 2000||23 Sep 2003||Coaxia, Inc.||Devices and methods for preventing distal embolization from the internal carotid artery using flow reversal by partial occlusion of the external carotid artery|
|US6623491||18 Jan 2001||23 Sep 2003||Ev3 Peripheral, Inc.||Stent delivery system with spacer member|
|US6623518||26 Feb 2001||23 Sep 2003||Ev3 Peripheral, Inc.||Implant delivery system with interlock|
|US6626886||20 Jul 2001||30 Sep 2003||Coaxia, Inc.||Devices and methods for preventing distal embolization during interventional procedures|
|US6626918||6 Oct 2000||30 Sep 2003||Medical Technology Group||Apparatus and methods for positioning a vascular sheath|
|US6632236||26 Jul 2001||14 Oct 2003||Arteria Medical Science, Inc.||Catheter having radially expandable main body|
|US6632238||20 Aug 2001||14 Oct 2003||Integrated Vascular Systems, Inc.||Vascular sheath with puncture site closure apparatus and methods of use|
|US6635070||21 May 2001||21 Oct 2003||Bacchus Vascular, Inc.||Apparatus and methods for capturing particulate material within blood vessels|
|US6638243||2 Aug 2002||28 Oct 2003||Target Therapeutics, Inc.||Balloon catheter with delivery side holes|
|US6638245||28 Feb 2002||28 Oct 2003||Concentric Medical, Inc.||Balloon catheter|
|US6641592||15 Nov 2000||4 Nov 2003||Lsi Solutions, Inc.||System for wound closure|
|US6645160||5 Jun 2000||11 Nov 2003||Christian M. Heesch||Guide support catheter|
|US6645222||17 Oct 2000||11 Nov 2003||Arteria Medical Science, Inc.||Puncture resistant branch artery occlusion device and methods of use|
|US6652480||10 Nov 1999||25 Nov 2003||Medtronic Ave., Inc.||Methods for reducing distal embolization|
|US6656152||16 Nov 2001||2 Dec 2003||Ad-Tech Medical Instrument Corp.||Drug delivery catheter assembly with inflatable balloon|
|US6663652||30 May 2002||16 Dec 2003||John M. K. Daniel||Distal protection device and method|
|US6669721||22 Feb 2001||30 Dec 2003||New York University||Endovascular thin film devices and methods for treating and preventing stroke|
|US6673040||27 Aug 1999||6 Jan 2004||Cardeon Corporation||System and methods for catheter procedures with circulatory support in high risk patients|
|US6682505||19 Jul 2001||27 Jan 2004||Arteria Medical Science, Inc.||Catheter for removing emboli from saphenous vein grafts and native coronary arteries|
|US6695861||7 Mar 2003||24 Feb 2004||Interrad Medical, Inc.||Sutureless retention device|
|US6695867||21 Feb 2002||24 Feb 2004||Integrated Vascular Systems, Inc.||Plunger apparatus and methods for delivering a closure device|
|US6702782||26 Jun 2001||9 Mar 2004||Concentric Medical, Inc.||Large lumen balloon catheter|
|US6711436||27 Sep 1999||23 Mar 2004||Duke University||Compositions, apparatus and methods for facilitating surgical procedures|
|US6730102||6 Nov 2000||4 May 2004||Abbott Laboratories||Systems, devices and methods for deploying needles|
|US6733517||12 Jun 2002||11 May 2004||Alsius Corporation||Angling introducer sheath for catheter having temperature control system|
|US6736790||11 Jul 2001||18 May 2004||Denise R. Barbut||Method and system for selective or isolated integrate cerebral perfusion and cooling|
|US6746457||7 Dec 2001||8 Jun 2004||Abbott Laboratories||Snared suture trimmer|
|US6749621||21 Feb 2002||15 Jun 2004||Integrated Vascular Systems, Inc.||Sheath apparatus and methods for delivering a closure device|
|US6749627||18 Jan 2001||15 Jun 2004||Ev3 Peripheral, Inc.||Grip for stent delivery system|
|US6755847||5 Oct 2001||29 Jun 2004||Scimed Life Systems, Inc.||Emboli capturing device and method of manufacture therefor|
|US6758854||25 Jun 1999||6 Jul 2004||St. Jude Medical||Splittable occlusion balloon sheath and process of use|
|US6764464||28 Nov 2001||20 Jul 2004||Rex Medical, L.P.||Introducer sheath with retainer|
|US6783511||12 Apr 2001||31 Aug 2004||Heartport, Inc.||Methods and devices for occluding a patient's ascending aorta and delivering oxygenated blood to the patient|
|US6790197||25 Sep 2002||14 Sep 2004||Becton Dickinson And Company||Single use syringe and plunger rod locking device therefor|
|US6827730||23 Nov 2001||7 Dec 2004||Endovascular Technologies, Inc.||Reduced diameter stent/graft deployment catheter|
|US6830579||1 May 2001||14 Dec 2004||Coaxia, Inc.||Devices and methods for preventing distal embolization using flow reversal and perfusion augmentation within the cerebral vasculature|
|US6837881||2 Jul 2003||4 Jan 2005||Coaxia, Inc.||Devices and methods for preventing distal embolization using flow reversal by partial occlusion of the brachiocephalic artery|
|US6840949||12 Mar 2003||11 Jan 2005||Coaxia, Inc.||Devices and methods for preventing distal embolization using flow reversal in arteries having collateral blood flow|
|US6847234||14 Jul 2003||25 Jan 2005||Hynix Semiconductor Inc.||Comparison apparatus operated at a low voltage|
|US6849068||6 Dec 1999||1 Feb 2005||Medtronic Ave, Inc.||Aspiration catheter|
|US6855136 *||25 Apr 2002||15 Feb 2005||Gore Enterprise Holdings, Inc.||Infusion catheter having an atraumatic tip|
|US6875231||11 Sep 2002||5 Apr 2005||3F Therapeutics, Inc.||Percutaneously deliverable heart valve|
|US6878140||6 May 2003||12 Apr 2005||Coaxia, Inc.||Methods for flow augmentation in patients with occlusive cerebrovascular disease|
|US6884235||2 Jul 2002||26 Apr 2005||Rex Medical, L.P.||Introducer sheath with retainer and radiopaque insert|
|US6887227||23 Feb 2001||3 May 2005||Coaxia, Inc.||Devices and methods for preventing distal embolization from the vertebrobasilar artery using flow reversal|
|US6902540||4 Oct 2001||7 Jun 2005||Gerald Dorros||Apparatus and methods for treating stroke and controlling cerebral flow characteristics|
|US6905490||16 Nov 2001||14 Jun 2005||Gore Enterprise Holdings, Inc.||Apparatus and methods for reducing embolization during treatment of carotid artery disease|
|US6905505||12 Apr 2002||14 Jun 2005||Kensey Nash Corporation||System and method of use for agent delivery and revascularizing of grafts and vessels|
|US6908474||15 Mar 2002||21 Jun 2005||Gore Enterprise Holdings, Inc.||Apparatus and methods for reducing embolization during treatment of carotid artery disease|
|US6929634||1 Apr 2002||16 Aug 2005||Gore Enterprise Holdings, Inc.||Apparatus and methods for treating stroke and controlling cerebral flow characteristics|
|US6932824||2 Mar 2004||23 Aug 2005||St. Jude Medical Puerto Rico B.V.||Three-needle closure device|
|US6936060||14 Mar 2002||30 Aug 2005||Arteria Medical Sciences, Inc.||Apparatus and methods for removing emboli during a surgical procedure|
|US6942674||21 Feb 2002||13 Sep 2005||Integrated Vascular Systems, Inc.||Apparatus and methods for delivering a closure device|
|US6958059||28 Dec 2001||25 Oct 2005||Medtronic Ave, Inc.||Methods and apparatuses for drug delivery to an intravascular occlusion|
|US6964668||20 May 2002||15 Nov 2005||Abbott Laboratories||Articulating suturing device and method|
|US6972030||13 Dec 2002||6 Dec 2005||Lee Don W||Stent with combined distal protection device|
|US6979346||8 Aug 2001||27 Dec 2005||Advanced Cardiovascular Systems, Inc.||System and method for improved stent retention|
|US7001398||9 Jul 2003||21 Feb 2006||Integrated Vascular Systems, Inc.||Closure device and methods for making and using them|
|US7001400||29 Aug 2000||21 Feb 2006||Abbott Laboratories||Articulating suturing device and method|
|US7004924||19 Oct 1998||28 Feb 2006||Nxstage Medical, Inc.||Methods, systems, and kits for the extracorporeal processing of blood|
|US7004931 *||21 Oct 2002||28 Feb 2006||Gore Enterprise Holdings, Inc.||Proximal catheter assembly having a self-limiting aspiration valve|
|US7022100||1 Sep 2000||4 Apr 2006||A-Med Systems, Inc.||Guidable intravascular blood pump and related methods|
|US7029480||30 Dec 2002||18 Apr 2006||Abott Laboratories||Device and method for suturing of internal puncture sites|
|US7029487||4 Dec 2002||18 Apr 2006||Microvention, Inc.||Vascular embolization with an expansible implant|
|US7029488||21 Oct 2002||18 Apr 2006||Gore Enterprise Holdings, Inc.||Mechanical thrombectomy device for use in cerebral vessels|
|US7033344||5 Aug 2002||25 Apr 2006||Medtronic Vascular, Inc.||Methods for reducing distal embolization|
|US7048747||20 Nov 2001||23 May 2006||Abbott Laboratories||Device and method for performing end-to-side anastomosis|
|US7048758||6 Jun 2003||23 May 2006||Advanced Cardiovascular Systems, Inc.||Vessel occlusion device for embolic protection system|
|US7063714||4 Oct 2001||20 Jun 2006||Gore Enterprise Holdings, Inc.||Apparatus and methods for treating stroke and controlling cerebral flow characteristics|
|US7083594||24 Jun 2003||1 Aug 2006||Invatec S.R.L.||Endovascular system for the treatment of stenoses of the carotid and catheter for this system|
|US7090686||12 May 2003||15 Aug 2006||Sutura, Inc.||Suturing device and method|
|US7094246||12 Sep 2003||22 Aug 2006||Abbott Laboratories||Suture trimmer|
|US7104979||19 Feb 2002||12 Sep 2006||Target Therapeutics, Inc.||Catheter with composite stiffener|
|US7108677||31 May 2001||19 Sep 2006||Kerberos Proximal Solutions, Inc.||Embolization protection system for vascular procedures|
|US7144386||5 Aug 2003||5 Dec 2006||Ab Korkor Medical, Inc.||Catheter introducer having an expandable tip|
|US7144411||23 Sep 2003||5 Dec 2006||Integrated Vascular Systems, Inc.||Apparatus and methods for positioning a vascular sheath|
|US7150712||5 Aug 2002||19 Dec 2006||Buehlmann Eric L||Target tissue localization assembly and method|
|US7152605||16 May 2003||26 Dec 2006||Ev3 Endovascular, Inc.||Adjustable left atrial appendage implant deployment system|
|US7166088||27 Jan 2003||23 Jan 2007||Heuser Richard R||Catheter introducer system|
|US7172621||24 Sep 2004||6 Feb 2007||Laurence Theron||Method of performing protected angioplasty and stenting at a carotid bifurcation|
|US7208008||2 Oct 2003||24 Apr 2007||Medtronic Vascular, Inc.||Balloonless direct stenting device|
|US7232452||12 Jul 2002||19 Jun 2007||Ev3 Inc.||Device to create proximal stasis|
|US7232453||5 Dec 2002||19 Jun 2007||Sagax, Inc.||Endovascular device for entrapment of particulate matter and method for use|
|US7250042||22 Jan 2004||31 Jul 2007||Nipro Corporation||Thrombus suction catheter with improved suction and crossing|
|US7306585||30 Sep 2004||11 Dec 2007||Engineering Resources Group, Inc.||Guide catheter|
|US7309334||21 Jul 2003||18 Dec 2007||Von Hoffmann Gerard||Intracranial aspiration catheter|
|US7367982||1 Nov 2004||6 May 2008||Kensey Nash Corporation||Method for opening a lumen in an occluded blood vessel|
|US7374560||29 Aug 2001||20 May 2008||St. Jude Medical, Cardiology Division, Inc.||Emboli protection devices and related methods of use|
|US7374561||30 Sep 2003||20 May 2008||Coaxia, Inc.||Devices and methods for preventing distal embolization during interventional procedures|
|US7390328||19 Dec 2003||24 Jun 2008||Abbott Laboratories||Device and method for suturing of internal puncture sites|
|US7396359||30 May 1999||8 Jul 2008||Bypass, Inc.||Vascular port device|
|US7402151||17 Dec 2004||22 Jul 2008||Biocardia, Inc.||Steerable guide catheters and methods for their use|
|US7422579||1 May 2001||9 Sep 2008||St. Jude Medical Cardiology Divison, Inc.||Emboli protection devices and related methods of use|
|US7458980||11 Jan 2005||2 Dec 2008||Coaxia, Inc.||Devices and methods for preventing distal embolization using flow reversal in arteries having collateral blood flow|
|US7524303||21 Jun 2004||28 Apr 2009||T. Anthony Don Michael||Arterial obstruction treatment kit|
|US7534250||27 Jun 2003||19 May 2009||Cook Critical Care||Introducer sheath|
|US7731683||6 Sep 2005||8 Jun 2010||Boston Scientific Scimed, Inc.||Endoluminal occlusion-irrigation catheter with aspiration capabilities and methods of use|
|US7766049||22 Oct 2003||3 Aug 2010||Concentric Medical, Inc.||Balloon catheter|
|US7766820||24 Oct 2003||3 Aug 2010||Nmt Medical, Inc.||Expandable sheath tubing|
|US7815626||12 Jun 1998||19 Oct 2010||Target Therapeutics, Inc.||Catheter with knit section|
|US7867216||19 Jan 2006||11 Jan 2011||St. Jude Medical, Cardiology Division, Inc.||Emboli protection device and related methods of use|
|US7905856||21 Mar 2005||15 Mar 2011||Rex Medical, L.P.||Introducer sheath with retainer|
|US7905877||12 May 2006||15 Mar 2011||Micrus Design Technology, Inc.||Double helix reinforced catheter|
|US7909812||6 Sep 2006||22 Mar 2011||Target Therapeutics, Inc.||Catheter with composite stiffener|
|US7927309||29 May 2007||19 Apr 2011||Cordis Corporation||Expandable sheath introducer|
|US7972308||4 Apr 2007||5 Jul 2011||Ad-Tech Medical Instrument Corp.||Intracranial catheter assembly for precise treatment of brain tissue|
|US8029533||4 Apr 2008||4 Oct 2011||Accessclosure, Inc.||Apparatus and methods for sealing a vascular puncture|
|US8066757||28 Dec 2010||29 Nov 2011||Mindframe, Inc.||Blood flow restoration and thrombus management methods|
|US8152782||20 May 2010||10 Apr 2012||Boston Scientific Scimed, Inc.||Endoluminal occlusion-irrigation catheter with aspiration capabilities and methods of use|
|US8181324||18 Oct 2010||22 May 2012||Target Therapeutics, Inc.||Catheter with knit section|
|US8221348||7 Jul 2005||17 Jul 2012||St. Jude Medical, Cardiology Division, Inc.||Embolic protection device and methods of use|
|US8231600||7 Nov 2007||31 Jul 2012||Onset Medical Corporation||Intracranial aspiration catheter|
|US20010044598||15 Oct 1999||22 Nov 2001||Nicola A. Pisano||Apparatus and methods for reducing embolization during treatment of carotid artery disease|
|US20010044634||12 Mar 2001||22 Nov 2001||Don Michael T. Anthony||Vascular embolism prevention device employing filters|
|US20010044638||13 Mar 2001||22 Nov 2001||Scion Cardio-Vascular, Inc.||Suture with toggle and method of manufacture therefor|
|US20010049517||16 Mar 1999||6 Dec 2001||Gholam-Reza Zadno-Azizi||Method for containing and removing occlusions in the carotid arteries|
|US20020052620||29 Oct 2001||2 May 2002||Coaxia, Inc.||Medical device for removing thromboembolic material from cerebral arteries and methods of use|
|US20020052640||29 Jun 2001||2 May 2002||Steve Bigus||Sheath for self-expanding stents|
|US20020068899||28 Nov 2001||6 Jun 2002||Rex Medical||Introducer sheath with retainer|
|US20020077600||19 Dec 2000||20 Jun 2002||Laksen Sirimanne||Percutaneous catheter assembly|
|US20020087119||16 Nov 2001||4 Jul 2002||Arteria Medical Science, Inc.||Apparatus and methods for reducing embolization during treatment of carotid artery disease|
|US20020128679||8 Mar 2001||12 Sep 2002||Embol-X, Inc.||Cerebral protection during carotid endarterectomy and methods of use|
|US20020173815||15 Mar 2002||21 Nov 2002||Michael Hogendijk||Apparatus and methods for reducing embolization during treatment of carotid artery disease|
|US20030040762||4 Oct 2001||27 Feb 2003||Gerald Dorros||Apparatus and methods for treating stroke and controlling cerebral flow characteristics|
|US20030050600||9 Aug 2002||13 Mar 2003||Velocimed, L.L.C.||Emboli protection devices and related methods of use|
|US20030065356||12 Nov 2002||3 Apr 2003||Embol-X, Inc.||Methods of protecting a patient from embolization during surgery|
|US20030069468||6 Nov 2002||10 Apr 2003||Bolling Steven F.||Implantable heart assist system and method of applying same|
|US20030186203||9 Jan 2003||2 Oct 2003||Aboud Emad T.||Method and apparatus for surgical training|
|US20030212304||14 Mar 2003||13 Nov 2003||Lattouf Omar M.||Systems and method for practicing counter-cardiac retrograde perfusion|
|US20040116946||6 Oct 2003||17 Jun 2004||St. Jude Medical Atg, Inc.||Medical grafting methods and apparatus|
|US20040127913||31 Dec 2002||1 Jul 2004||Voss Laveille Kao||Systems for anchoring a medical device in a body lumen|
|US20040210251||17 Apr 2003||21 Oct 2004||Stavros Kontos||Surgical device|
|US20040249435||9 Jun 2003||9 Dec 2004||Xtent, Inc.||Stent deployment systems and methods|
|US20050096726||29 Oct 2004||5 May 2005||Jacques Sequin||Noncylindrical stent deployment system for treating vascular bifurcations|
|US20050124973||20 Jan 2005||9 Jun 2005||Gerald Dorros||Apparatus and methods for treating stroke and controlling cerebral flow characteristics|
|US20050131453 *||27 Jan 2005||16 Jun 2005||Parodi Juan C.||Apparatus and methods for reducing embolization during treatment of carotid artery disease|
|US20050149065||19 Dec 2003||7 Jul 2005||Modesitt D. B.||Device and method for suturing of internal puncture sites|
|US20050154344||22 Nov 2004||14 Jul 2005||Chang David W.||Method and apparatus for treating a carotid artery|
|US20050154349||5 Nov 2004||14 Jul 2005||Playtex Products, Inc.||Manual breast pump|
|US20050228402||24 Jan 2003||13 Oct 2005||Lawrence Hofmann||Methods and devices for percutaneous and surgical interventions|
|US20050228432||20 Jun 2005||13 Oct 2005||Michael Hogendijk||Apparatus and methods for reducing embolization during treatment of carotid artery disease|
|US20050251162||29 Sep 2004||10 Nov 2005||Usgi Medical Inc.||Apparatus and methods for manipulating and securing tissue|
|US20050267323||6 Jun 2005||1 Dec 2005||Gerald Dorros||Apparatus and methods for treating stroke and controlling cerebral flow characteristics|
|US20050273051||28 Jul 2005||8 Dec 2005||Invatec S.R.I||Endovascular system for the treatment of stenoses of the carotid and catheter for this system|
|US20060111741||23 Nov 2004||25 May 2006||Instrasurgical, Llc||Wound closure device|
|US20060149350||5 Dec 2005||6 Jul 2006||Flowmedica, Inc.||Systems and methods for performing bi-lateral interventions or diagnosis in branched body lumens|
|US20060167437||16 Dec 2005||27 Jul 2006||Flowmedica, Inc.||Method and apparatus for intra aortic substance delivery to a branch vessel|
|US20060167476||27 Mar 2006||27 Jul 2006||Perclose, Inc||Systems, devices and methods for suturing patient tissue|
|US20060200191||2 May 2006||7 Sep 2006||Gholam-Reza Zadno-Azizi||Method and apparatuses for treating an intravascular occlusion|
|US20060282088||8 Jun 2005||14 Dec 2006||Ryan Timothy J||Apparatus and methods for delivering sutures|
|US20060287673||28 Apr 2006||21 Dec 2006||Zerusa Limited||Interventional medical closure device|
|US20070123925||28 Nov 2005||31 May 2007||Medtronic Vascular, Inc.||Pre-curved guiding catheter with mechanically actuated anchor|
|US20070123926||28 Nov 2005||31 May 2007||Medtronic Vascular, Inc.||Pre-curved guiding catheter with mechanically actuated occluder for embolic protection|
|US20070198049||17 Apr 2007||23 Aug 2007||Coaxia, Inc.|
|US20070249997||26 Jun 2007||25 Oct 2007||Flowmedica, Inc.||Method and apparatus for selective material delivery via an intra-renal catheter|
|US20070270888||16 May 2006||22 Nov 2007||Joel Kwan Barrientos||Catheter having end including grooved needle guides|
|US20080045979||18 Aug 2006||21 Feb 2008||Abbott Laboratories||Articulating suture device and method|
|US20080058839||6 Feb 2007||6 Mar 2008||Nobles Anthony A||Reverse tapered guidewire and method of use|
|US20080086164||2 Apr 2007||10 Apr 2008||Rowe Stanton J||Method and apparatus for reshaping a ventricle|
|US20080097479||20 Oct 2006||24 Apr 2008||Raimar Boehlke||Device and method for vascular closure|
|US20080140010||12 Sep 2007||12 Jun 2008||Wilson-Cook Medical Inc.||Medical catheter with stress riser at access port to reduce rupture force|
|US20080188890||28 Nov 2007||7 Aug 2008||Barry Weitzner||Multi-part instrument systems and methods|
|US20080200946||1 Feb 2008||21 Aug 2008||Reverse Medical Corporation||Occlusion device and method of use|
|US20080208329||22 Oct 2007||28 Aug 2008||Gordon Bishop||Handle mechanism to adjust a medical device|
|US20080221614||9 Mar 2007||11 Sep 2008||Medtronic Vascular, Inc.||Method for Closing an Arteriotomy|
|US20080287967||30 Jul 2008||20 Nov 2008||Abbott Laboratories||Device and Methods for Suturing Tissue|
|US20090018455||18 Jul 2008||15 Jan 2009||Silk Road Medical, Inc.||Method and apparatus for treating a carotid artery|
|US20090024072||18 Jul 2008||22 Jan 2009||Enrique Criado||Methods and systems for establishing retrograde carotid arterial blood flow|
|US20090143789||31 Oct 2008||4 Jun 2009||Houser Russell A||Vascular closure devices, systems, and methods of use|
|US20090198172||21 Jan 2009||6 Aug 2009||Garrison Michi E||Interventional sheath with retention features|
|US20090254166||5 Feb 2009||8 Oct 2009||Chou Tony M||Interventional catheter system and methods|
|US20100042118||12 Aug 2009||18 Feb 2010||Garrison Michi E||Suture delivery device|
|US20100114002||10 Oct 2009||6 May 2010||O'mahony John J||Method and apparatus for an extracorporeal control of blood glucose|
|US20100185216||8 Dec 2009||22 Jul 2010||Garrison Michi E||Suture delivery device|
|US20100280431||13 Jul 2010||4 Nov 2010||Enrique Criado||Methods and systems for establishing retrograde carotid arterial blood flow|
|US20110034986||12 Jul 2010||10 Feb 2011||Chou Tony M||Systems and methods for treating a carotid artery|
|US20110166497||17 Mar 2011||7 Jul 2011||Enrique Criado||Methods and systems for establishing retrograde carotid arterial blood flow|
|USRE34633||25 Jan 1993||7 Jun 1994||Cook Incorporated||Balloon guide|
|USRE43300||18 Apr 2002||3 Apr 2012||Abbott Cardiovascular Systems Inc.||Apparatus having stabilization members for percutaneously performing surgery and methods of use|
|EP0427429A2||25 Oct 1990||15 May 1991||C.R. Bard, Inc.||Occluding catheter for treating cerebral arteries|
|EP0669103B1||23 Feb 1995||29 Sep 1999||LaserSurge, Inc.||Surgical crimping device|
|EP1649829A1||14 Oct 2005||26 Apr 2006||Kieran P. Murphy||Stent delivery system with a balloon for a self-expandable stent|
|JP2005523123A||Title not available|
|1||Adami, M.D., et al., (2002) "Use of the Parodi Anti-Embolism System in Carotid Stenting: Italian Trial Results" J Endovasc Ther 9:147-154.|
|2||Alexandrescu et al. (2006) "Filter-protected carotid stenting via a minimal cervical access with transitory aspirated reversed flow during initial passage of the target lesion" J. Endovasc. Ther. 13(2):196-204.|
|3||Alvarez et al. (2008). "Transcervical carotid stenting with flow reversal is safe in octogenarians: A preliminary safety study" J. Vasc. Surg. 47:96-100.|
|4||Bates M.D., et al. "Reversal of the Direction of Internal Carotid Artery Blood Flow by Occlusion of the Common and External Carotid Arteries in a Swine Model" Catherization and Cardiovascular Intervention 60:270-275 (2003).|
|5||Bates, M.D., et al. (2004) "Internal Carotid Artery Flow Arrest/Reversal Cerebral Protection Techniques" The West Virginal Medical Journal, vol. 99:60-63.|
|6||Bergeron et al. (1999). "Percutaneous stenting of the internal carotid artery: the European CAST I Study" J. Endovasc. Surg. 6:155-159.|
|7||Bergeron et al. (2008) MEET Presentation, Cannes, French Riviera "Why I do not use routine femoral access for CAS".|
|8||Bergeron P. et al. (1996) "Recurrent Carotid Disease: Will Stents be an alternative to surgery?" J Endovasc Surg; 3: 76-79.|
|9||Bettman, M. et al, "Carotid Stenting and Angioplasty . . . ", etc. Circulation, 1998, 97:121-123.|
|10||Chang, D.W., et al, "A new approach to carotid angioplasty and stenting with transcervical occlusion and protective shunting: Why it may be a better carotid artery intervention" (J Vasc Surg 2004; 39:994-1002.).|
|11||Chang, M.D., "Carotid Angioplasty and Stenting Using Transcervical Occlusion and Protective Shunting Via a Mini Incision in the Neck: A New Technique for Difficult Femoral Access or Filter Placement may be the Better Carotid Artery Intervention" 30th Global: Vascular and Endovascular Issues, Techniques and Horizons. XXVII 6.1-XXVII 6.2.|
|12||Coppi et al. (2005). "PRIAMUS Proximal flow blockage cerebral protection during carotid stenting: Results from a multicenter Italian regiStry" J. Cardiovasc. Surg. 46:219-227.|
|13||Criado et al. (1997) "Evolving indications for and early results of carotid artery stenting" Am. J. Surg.; 174:111-114.|
|14||Criado et al. (2004). "Transcervical carotid artery angioplasty and stenting with carotid flow reversal: Surgical technique" J. Vasc. Surg. 18:257-261.|
|15||Criado et al. (2004). "Transcervical carotid stenting with internal carotid artery flow reversal: Feasibility and preliminary results" J. Vasc. Surg. 40:476-483.|
|16||Criado, et al. (2007). "Transcervical carotid stenting with carotid artery flow reversal: 3-year follow-up of 103 stents." J Vasc Surg 46(5): 864-9.|
|17||Criado, F.J., et al., Access strategies for carotid artery intervention. J Invasive Cardiol, 2000. 12(1): p. 61-8.|
|18||Criado, M.D., et al. (2004) "Carotid angioplasty with internal carotid artery flow reversal is well tolerated in the awake patient" Journal of Vascular Surgery, 40(1):92-7.|
|19||Diederich et al. (2004) "First Clinical experiences with an endovascular clamping system for neuroprotection during carotid stenting" Eur. J. Vasc. Endovasc. Surg. 28:629-633.|
|20||Diethrich et al., (1996). "Percutaneous techniques for endoluminal carotid interventions" J. Endovasc. Surg. 3:182-202.|
|21||Diethrich, E. B. (2004). The Direct Cervical Carotid Artery Approach. Carotid Artery Stenting: Current Practice and Techniques. N. Al-Mubarak, G. S. Roubin, S. Iyer and J. Vitek. Philadephia, Lippincott Williams & Wilkins: Chapter 11. pp. 124-136.|
|22||Feldtman, R. W., C. J. Buckley, et al. (2006). "How I do it: cervical access for carotid artery stenting." Am J Surg 192(6): 779-81.|
|23||Goldstein "Acute Ischemic Stroke Treatment in 2007" Circ 116:1504-1514 (2007).|
|24||Gray et al. (2007) "The Capture registry: Results of carotid stenting with embolic protection in the post approval setting" Cath. Cardovasc. Interven. 69:341-348.|
|25||Henry et al. (1999) "Carotid stenting with cerebral protection: First clinical experience using the PercuSurge GuardWire System" J. Endovasc. Surg. 6:321-331.|
|26||Lin et al. (2005) "Protected carotid artery stenting and angioplasty via transfemoral versus transcervical approaches" Vasc. Endovasc. Surg. 39(6):499-503.|
|27||Lo et al. (2005) "Advantages and indications of transcervical carotid artery stenting with carotid flow reversal" J. Cardovasc. Surg (Torino). 46(3):229-239.|
|28||Luebke, T et al. (2007) "Meta-analysis of randomized trials comparing carotid endarterectomy and endovascular treatment" Eur. J. Vasc. Endovasc. Surg. 34:470-479.|
|29||MacDonald, S. (2006) "Is there any evidence that cerebral protection is beneficial?" J. Cardiovasc. Surg. 47:127-36.|
|30||Mas et al. (2006) "Endarterectomy versus stenting in patients with symptomatic severe carotid stenosis" NEJM 355:1660-71.|
|31||Matas et al. (2007). "Transcervical carotid stenting with flow reversal protection: Experience in high-risk patients" J. Vasc. Surg. 46:49-54.|
|32||MO.MA Brochure; Proximal Flow Blockage Cerebral Protection Device-INVATEC.|
|33||MO.MA Brochure; Proximal Flow Blockage Cerebral Protection Device—INVATEC.|
|34||MomaPresn (AET) 2002 Biamino, G; MO.MA as a distal protective device, University of Leipzig-Heart Center Department of Clinical and Interventional; Angiology Leipzig, Germany; 2002.|
|35||MomaPresn (AET) 2002 Biamino, G; MO.MA as a distal protective device, University of Leipzig—Heart Center Department of Clinical and Interventional; Angiology Leipzig, Germany; 2002.|
|36||Ohki, M.D., et al., "Efficacy of a proximal occlusion catheter with reversal of flow in the prevention of embolic events during carotid artery stenting: An experimental analysis" (J Vasc Surg 2001; 33:504-9).|
|37||Ouriel, K., R. K. Greenberg, et al. (2001). "Hemodynamic conditions at the carotid bifurcation during protective common carotid occlusion." J Vasc Surg 34(4): 577-80.|
|38||Parodi (2005). "Is flow reversal the best method of protection during carotid stenting?" J Endovasc. Ther. 12:166-170.|
|39||Parodi et al. (2000). "Initial evaluation of carotid angioplasty and stenting with three different cerebral protection devices" J. Vasc. Surg. 32:1127-1136.|
|40||Parodi, J. C., L. M. Ferreira, et al. (2005). "Cerebral protection during carotid stenting using flow reversal." J Vasc Surg 41(3): 416-22.|
|41||Perez-Arjona, E. A., Z. DelProsto, et al. (2004). "Direct percutaneous carotid artery stenting with distal protection: technical case report." Neurol Res 26(3): 338-41.|
|42||Pipinos et al. (2005). "Transcervical approach with protective flow reversal for carotid angioplasty and stenting" J. Endovasc. Ther. 12:446-453.|
|43||Pipinos et al. (2006). "Transcervical carotid stenting with flow reversal for neuroprotection: Technique, results, advantages, and limitations" 14(5):245-255.|
|44||Reekers, J. A. (1998). "A balloon protection sheath to prevent peripheral embolization during aortoiliac endovascular procedures." Cardiovasc Intervent Radiol 21(5): 431-3.|
|45||Reimers et al. (2005). "Proximal endovascular flow blockage for cerebral protection during carotid artery stenting: Results from a prospective multicenter registry" J. Endovasc. Ther. 12:156-165.|
|46||Ribo et al. (2006). "Transcranial doppler monitoring of transcervical carotid stenting with flow reversal protection: a novel carotid revascularization technique" 27:2846-2849 (originally published online Sep. 28, 2006).|
|47||Stecker et al., (2002). "Stent placement in common carotid and internal carotid artery stenoses with use of an open transcervical approach in a patient with previous endarterectomy" J. Vasc. Interv. Radiol. 13:413-417.|
|48||Stejskal, et al., "Experience of 500 Cases of Neurophysiological Monitoring in Carotid Endarterectomy", Acta Neurochir, 2007, 149:681-689.|
|49||Theron, et al. "New Triple Coaxial Catheter System for Carotid Angioplasty with Cerebral Protection" AJNR 11:869-874, Sep./Oct. 1990 0195-6108/90/1106-0869 @ American Society of Neurology.|
|U.S. Classification||604/9, 623/1.11|
|International Classification||A61M5/00, A61F2/06, A61F2/90|
|Cooperative Classification||A61M2205/3334, A61M2205/33, A61M1/36, A61M39/22, A61M39/06, A61M25/10, A61M5/007, A61M1/3655, A61F2/95, A61B2017/12127, A61B17/12109, A61B17/12045, A61B8/488, A61B8/06, A61M2205/3331, A61M1/34, A61F2/82, A61F2250/0037, A61F2/90, A61B2017/320716, A61F2/954, A61M1/3613, A61B2017/00778, A61M2025/1052, A61M29/02, A61F2002/065, A61M1/3659|
|8 Jun 2011||AS||Assignment|
Owner name: SILK ROAD MEDICAL, INC., CALIFORNIA
Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:CRIADO, ENRIQUE;CHOU, TONY M.;GARRISON, MICHI E.;AND OTHERS;SIGNING DATES FROM 20080903 TO 20080911;REEL/FRAME:026412/0488
|13 Oct 2015||AS||Assignment|
Owner name: CRG PARTNERS III - PARALLEL FUND "A" L.P., TEXAS
Free format text: SECURITY INTEREST;ASSIGNOR:SILK ROAD MEDICAL, INC.;REEL/FRAME:036852/0347
Effective date: 20151013
Owner name: CRG PARTNERS III - PARALLEL FUND "B" (CAYMAN) L.P.
Free format text: SECURITY INTEREST;ASSIGNOR:SILK ROAD MEDICAL, INC.;REEL/FRAME:036852/0347
Effective date: 20151013
Owner name: CRG PARTNERS III (CAYMAN) L.P., TEXAS
Free format text: SECURITY INTEREST;ASSIGNOR:SILK ROAD MEDICAL, INC.;REEL/FRAME:036852/0347
Effective date: 20151013
Owner name: CRG PARTNERS III L.P., TEXAS
Free format text: SECURITY INTEREST;ASSIGNOR:SILK ROAD MEDICAL, INC.;REEL/FRAME:036852/0347
Effective date: 20151013